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This report has been reproduced directly from the best available copy.

Available to DOE and DOE contractors from the Office of Scientific and Technical Information, P.O. Box 62, Oak Ridge, TN 37831; prices available from (615) 576-8401,

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DOE/ER-0529P

UC-402

Summaries of FY 1991

Engineering Research

November 1991

U.S. Department of Energy

Office of Energy Research

Office of Basic Energy Sciences

Division of Engineering and Geosciences

Washington, D. C. 20585
Foreword

This report documents the BES Engineering Research Program for fiscal year 1991; it

provides a summary for each of the program projects in addition to a brief program

overview. The report is intended to provide staff of Congressional committees, other

executive departments, and other DOE offices with substantive program information so as

to facilitate governmental overview and coordination of Federal research programs. Of

equal importance, its availability facilitates communication of program information to

interested research engineers and scientists. The organizational chart for the DOE Office

of Energy Research (OER) on the next page delineates the six Divisions within the OER

Office of Basic Energy Sciences (BES). Each BES Division administers basic, mission

oriented research programs in the area indicated by its title. The BES Engineering

Research Program is one such program; it is administered by the Engineering and

Geosciences Division of BES. Dr. Oscar P. Manley is technical manager of the

Engineering Research Program; inquiries concerning the program may be addressed to

him, in writing or by phone at (301) 903-5822.

In preparing this report we asked the principal investigators to submit summaries for their

projects that were specifically applicable to fiscal year 1991. The summaries received have

been edited if necessary, but the press for timely publication made it impractical to have

the investigators review and approve the summaries prior to publication. For more

information about a given project, it is suggested that the investigators be contacted

directly.
ENGINEERING RESEARCH PROGRAM WITHIN DOE

Secretary of Energy

Deputy Secretary

Under Secretary

Assistant Secretaries Office of Energy Research * Federal Energy Regulatory

· Nuclear Energy .- Commission

· Conservation and Renewable * Economic Regulatory

· Fossil Commission · Defense * Energy Information

· Environment, Safety & Health Administration · Environmental Restoration * International Affairs, etc.

* Program Analysis Basic Energy Sciences

* Magnetic Fusion Management * High Energy and Nuclear Physics Spcial Programs

* Health and Environmental Research * Scientific Computing

* •Field Operations Operations * Science and Technology Advisor

* Material Sciences Division Engineering and * Advanced Energy Projects

* Chemicai Sciences Division Geosciences Division * Energy Biosciences

Engineering

Research Program
Introduction

The individual project summaries follow the program overview. The summaries are

ordered alphabetically by name of institution and so the table of contents lists all the

institutions at which projects were sponsored in fiscal year 1991.

The projects are numbered sequentially for individual identification in the indexes. Each

project entry begins with an institutional-departmental heading. The names of investigators are listed immediately below the title. The funding level for fiscal year 1991

appears to the right of title; it is followed by the budget activity number (e.g.,01A). These

numbers categorize the projects for budgetary purposes and the categories are described

in the budget number index. The year in which either the project began or was renewed

and the anticipated duration in years are indicated respectively by the first two and last

digits of the sequence directly below the budget activity number (e.g., 90-3). The

summary description of the project completes the entry.
Program Review

BES Engineering Research

The BES Engineering Research Program is one of the component research programs which

collectively constitute the DOE Basic Energy Sciences Program. The DOE Basic Energy

Sciences program supports energy related research in the physical and biological sciences,

and in engineering. The chief purpose of the DOE Basic Energy Sciences Program is to

provide the fundamental scientific base on which identification and development of future,

national energy options will depend. The major product of the program becomes part of

the body of data and knowledge upon which the applied energy technologies are founded;

the product is knowledge relevant to energy exploration, production, conversion and use.

The BES Engineering Research Program was started in 1979 to help resolve the numerous

serious engineering issues arising from efforts to meet U.S. energy needs. The program

supports fundamental research on broad, generic topics in energy related engineering topics

not as narrowly scoped as those addressed by the shorter term engineering research projects

sponsored by the various DOE technology programs. Special emphasis is placed on

projects which, if successfully concluded, will benefit more than one energy technology.

During the first year several workshops were sponsored for the purpose of identifying

energy related engineering research needs and initial priorities. Representatives from

industry, academic institutions, national laboratories, and leading members of professional

organizations (Engineering Societies Commission of Energy, American Society of

Mechanical Engineers, Society of Automotive Engineers, and Joint Automation and Control

Committee) participated in the workshops. In addition to the participants in the workshops,

staff representatives from the DOE technology programs and other leading U.S. energy

engineering experts made significant contributions to the setting of program priorities.

There resulted from this process a strong confirmation of the need for a long range,

fundamental engineering research program with two major goals. The broad goals that

were established by this process for the BES Engineering Research Program are:

1) To extend the body of knowledge underlying current engineering practice so as to

create new options for enhancing energy savings and production, for prolonging useful

equipment life, and for reducing costs without degradation of industrial production and

performance quality; and

2) To broaden the technical and conceptual base for solving future engineering problems

in the energy technologies.
In this process, it was further established that to achieve these goals, the BES Engineering

Research Program should address the following topics identified as essential to the progress

of many energy technologies:

1) Advanced Industrial Technology: improvement of energy conversion and utilization,

opening new technological possibilities, and improvement of energy systems.

2) Fluid Dynamics and Thermal Processes: broadening of understanding of heat transfer

in nonsteady flows, methodology for reducing vibrations and noise in heat exchangers, and

engineering aspects of combustion.

3) Solid Mechanics: continuum mechanics, fracture mechanics, thermomechanical

behavior in severe environments, aging & lifetime reliability of structures.

4) Dynamics and Control of Processes and Systems: development and use of information

describing system behavior (system models), performance criteria, and theories of control

optimization to achieve the best possible system performance subject to known constraints.

A Scoping Workshop held in December, 1985 confirmed the continued needs for research

in these topical areas. Because of budgetary limitations, the implemented BES Engineering

Research Program is somewhat less broad than the program envisioned above. At present,

equal emphasis is being placed in three carefully selected, high priority research areas;

namely,

1) Mechanical Sciences including fluid mechanics (multiphase flow and turbulence) heat

transfer, and solid mechanics (continuum mechanics and fracture mechanics).

2) System Sciences including process control and instrumentation.

3) Engineering Analysis including nonlinear dynamics, data bases for thermophysical

properties of fluids, modeling of combustion processes for engineering application, and

foundations of bioprocessing of fuels and energy related wastes.

These areas contain the most critical elements of the four topics enumerated above; as such

they are of importance to energy technologies both in the short and long term, and

therefore of immediate programmatic interest. It should be noted that other areas of basic

research important to engineering are monitored elsewhere in BES. For instance,

separation sciences and research on thermophysical properties are among the

responsibilities of the Chemical Sciences Division, while microscopic aspects of fracture

mechanics are in the domain of the Material Sciences Division. As resources permit, other

high priority areas are being added to the Engineering Research Program. Thus, as a result

of previous growth in the program budget an important development took place in the

Engineering Research Program: two major concentrations of research were initiated.
First, a new program was organized at Oak Ridge National Lab dealing with intelligent

machines in an unstructured environment. Some resources are available for coordinated,

more narrowly focussed, related, high quality research at universities and other research

centers. All such activities are supported and administered directly by the Engineering

Research Program, but some coordination of efforts with the ORNL program may prove

useful.

Secondly in FY 1985, a collaborative research effort was started between MIT and Idaho

National Engineering Lab. At present, the collaboration is in three distinct areas: Plasma

Process Engineering, Automated Welding, and Fracture Mechanics. Collateral, high quality

research efforts at other institutions are supported by the Engineering Research Program.

In the expectation of a future modest growth of this Program, two International Workshops

on Two Phase Flow Fundamental were held one in September 1985 and the other in

March, 1987. The meetings were used to identify basic research needs in the field of two

phase flow and heat transfer; summary reports of the workshops are available from the

Program Office. The proceedings of the two workshops have been published as volumes

in the series "Advances in Heat and Mass Transfer" (Hemisphere Publishing Company)

Two additional workshops were held during 1988. The first dealt with possible research

opportunities in the field of novel devices using the new high temperature superconductors.

The second addressed research needs for bioprocessing of fuels and energy related wastes.

Reports of both workshops have been published. Additional funds have been provided in

FY 1992 to initiate research in the above mentioned bioprocessing area. Of interest are

relevant studies at the intersection of biology, biochemistry, and chemical engineering.

It should be mentioned too, that some very limited support is available for research on

large scale systems. A report of a workshop on needs, opportunities, and options in this

field is available from Professor G.L. Thompson, Graduate School of Industrial

Administration, Carnegie-Mellon University, Pittsburgh, PA 15213.

Research projects sponsored by the BES Engineering Research Program are currently

underway at universities, private sector laboratories, and DOE national laboratories. In

fiscal year 1991 the available program operating funds available amounted to about $14.8

million. The distribution of these funds among various institutions and by topical area is

illustrated on the next page. Project funding levels are mostly in the range of $50,000 to

$150,000 per year. Typical duration of a project is three to four years, with some projects

expected to last as long as ten years or more. The BES Engineering Research projects

stem almost without exception from proposals for competitive grants. Proposals which

anticipate definite results in less than two years are usually referred to the appropriate DOE

technology program for consideration. All those interested in submitting a proposal are
encouraged to discuss their ideas with the technical program manager prior to submission

of a formal proposal. Such discussion helps to establish whether or not a potential project

has a reasonable chance of being funded. The primary considerations for possible support

are the technical quality of the proposal and the professional standing of the principal

investigators and staff. An effort is made to attract first rate, younger research engineers

and energy oriented applied scientists. A high technical caliber of research is maintained

by requiring that the projects supported have potential for a significant contribution to

energy related engineering science, or for an initial contribution to a new energy relevant

technology. Sponsored projects are selected primarily for their relevance to DOE mission

requirements; the contribution to energy related higher education is an important but

secondary consideration. Thus projects sponsored at universities are essentially limited to

advanced theoretical and experimental studies usually performed by faculty members, staff

research scientists, and doctoral candidates.
ENGINEERING RESEARCH PROGRAM

FY '91 BUDGET ($000's)

BY INSTITUTIONAL TYPE

NATIONAL UNIVERSITIES

LABORATORIES 61%

29% $9022

$4228 A (99 PROJECTS)

(20 PROJECTS)

OTHER

10%

$1507

(12 PROJECTS)

ENGINEERING RESEARCH PROGRAM

FY '91 BUDGET

BY TECHNICAL AREAS

($000 s) %_ NUMBER OF PROJECTS

MECHANICAL SCIENCES 4934 33% 51

SYSTEMS SCIENCES 4818 33% 28

ENGINEERING ANALYSIS 5005 34% 52
Table of Contents

University of Alabama ............................... 1

Argonne National Laboratory ........................... 1

Arizona State University ............................. 2

Battelle Memorial Institute ............................. 3

Boston University ................................... 3

University Of California, Berkeley ....................... 4

University Of California, Los Angeles ..................... 4

University Of California, San Diego .................... .. 5

University Of California, Santa Barbara .................... 8

California Institute Of Technology ....................... 9

Carnegie Mellon University .................. ......... 9

University Of Chicago ............................... 10

Clarkson University ...................... .......... 11

University Of Connecticut .................. .......... 12

Cornell University .................................. 12

Dartmouth College ............... ................. 13

Duke University .................................... 14

Engineering Science Software, Inc ........................ 14

University Of Houston ............................... 15

Idaho National Engineering Laboratory .................... 15

University Of Illinois ................................ 18

University Of Illinois At Chicago ........................ 19

Jet Propulsion Laboratory ............................. 19

Johns Hopkins University ............................. 20

Robert H. Kraichnan, Inc. ............................. 20

Lawrence Berkeley Laboratory .......................... 20

Lovelace Medical Foundation ........................... 21

University Of Maryland .............................. 22

University Of Massachusetts ........................... 24

University Of Massachusetts-Lowell ...................... 24

Massachusetts Institute Of Technology .................... 25

University Of Minnesota .............................. 29

National Institute Of Standards And Technology .............. 30

The City University Of New York, The City College .......... 32

North Carolina State University ......................... 33

Northwestern University .............................. 33

University Of Notre Dame ............................. 35
Table of Contents (continued)

Oak Ridge National Laboratory ......................... 35

Ohio State University ....... ......................... 36

Oregon State University ............................. 37

Pacific Northwest Laboratory ........................... 37

University Of Pennsylvania ............................ 37

Physical Optics Corporation ........................... 38

Physical Sciences Inc ................................ 38

Princeton University ................................ 39

Purdue University ............................ 39

Rensselaer Polytechnic Institute ......................... 40

Rice University ............................. .. 42

University Of Rochester .............................. 42

Rockefeller University ............................. 43

Sandia National Laboratories ........................... 43

University Of Southern California ........................ 44

Southwest Research Institute ...................... .. 45

Stanford University ............................ 45

Stevens Institute Of Technology ......................... 49

Syracuse University ................................ 49

University Of Texas At Austin .......................... 49

Tufts University ............................ 50

United Technologies Research Center ..................... 50

Washington University ........................... 51

Washington State University ........................... 51

University Of Wisconsin ............................ 52
University Of Alabama Argonne National Laboratory

Dept of Mathematics $52,068 Materials & Components Tech Div $144,000

Tuscaloosa, AL 35487 01-C Argonne, IL 60439 01-A

91-3 90-3

Hydrodynamic Instabilities and Coherent Chaos in Fluid-Structure Systems

Structures S. Chen, T. Mulcahy

A. Frenkel

Integrated theoretical and experimental studies are

The objective of this project is to advance the being performed to enhance the understanding of

understanding of instabilities of several fluid nonlinear oscillations and dynamic instability

systems relevant to energy engineering sciences. phenomena involving both fluids and solid

Some problems, approaches to their solution, and structures and their coupling. The objectives are

results follow. to contribute to the explanation of observed

phenomena, providing insights into chaotic

For the problem of coherent structures and the characteristics of such coupled mechanical

inverse energy cascade in turbulent flows, both systems and ultimately, to the solution of

statistical ensembles and deterministic periodic engineering design problems. This is a joint

flows are considered. project with Professor F. Moon at Cornell

University.

It is found that an isotropic turbulent flow is stable

to the mean-flow perturbations. This suggests Fluidelastic instability of loosely supported tubes,

that some statistical anisotropy is necessary for vibrating in a tube support plate-inactive mode, is

the growth of the coherent structures. suspected to be one of the main causes of tube

failure in some operating steam generators and

The same techniques, based on mathematical heat exchangers. As a vehicle to understand the

insights into the properties of functionals of nonlinear behavior of fluid-structure systems,

Gaussian processes, yields a new description of fluidelastic instability of loosely supported tube

the diffusion of a passive scalar - such as the rows in crossflow is being studied in detail. Tube

temperature - in a turbulent flow. row with a motion-limiting stop configuration will

be tested to investigate various response

For a deterministic unidirectional flow with a characteristics and a mathematical model based

sinusoidal profile of velocity, it is shown rigorously on the unsteady flow theory will be developed to

- by using continued fractions - that some predict the response characteristics of this

perturbations which do not have the same classical fluid-structure system.

periodicity as the basic flow, can nevertheless

grow. The much more complicated case when the Energy systems have had a history of dynamic

flow is, in addition, sinusoidal in time is reduced to structural instabilities caused by fluid flow resulting

an infinite algebraic eigenvalue problem. Its in costly component repair and replacement and

Galerkin approximation results are not restricted to loss of energy production. The understanding of

large scales, in contrast to earlier results. An dynamic characteristics, including periodic

exact solution of a generalized Orr-Sommerfeld oscillations, random vibration, and chaotic motion,

equation in the inviscid case is found and will impact the design and reliability of these

compared to the Galerkin-based results. systems in both the near and long term. In

addition, fluid-structure systems are classical

For the core-annular flow - important in the examples of autonomous systems that can exhibit

lubricated pipelining of heavy oils - a new chaotic behavior. Knowledge of the fluid-structure

nonlinear interface equation is derived. It reflects systems may provide some insights into the

the dynamics of the core in addition to the chaotic behavior of other energy system

dynamics of the lubricating film. Several domains components.

of basic parameters are indicated in which the

instability cannot break up the flow. The finite but

small oscillations of the interface can have the

character of either deterministic chaos or else a

nonlinear propagating wave.

Engineering Research 1 1991
Argonne National Laboratory for this transition to be valid. For example, it was

Materials & Components Tech Div $132,000 demonstrated that the change in elastic

Argonne, IL 60439 01-A compliance is a proper choice for the

90-3 thermodynamic macro-flux since it represents an

Bounds on Dynamic Plastic Deformation orientation weighted volume average of microC. Youngdahl fluxes. The corresponding affinity is the energy

release rate integrated along the crack perimeter

Analytical studies are being performed to develop and averaged across its surface. The macromethods for approximating or bounding the potential is subsequently determined as an inner

dynamic plastic deformation of structures. In envelope of the micro-potential. The

many applications where the load is transmitted to corresponding damage surface is a convex

the structure through a fluid, details of the load piecewise smooth hypersurface possessing the

history and spatial distribution significantly affect normality property. The ensuing computations

the final plastic deformation. The objective of the clearly indicate the simplicity and accuracy of the

program is to devise mode approximation methods proposed model in several illustrative examples.

and load correlation parameters which can be

used to predict the final deformed shape and The micro-to-macro transition is, however, proven

characterize the effects of the load without to be valid only as long as the application of the

resorting to detailed numerical analyses. These effective contnua theories is justified. In other

approximation methods have three important uses: words, the macro flow potential cannot be proven

to perform design and safety analyses of to exist when the influence of the direct interaction

structures over a wide range of design variables of micro-defects on the deformation becomes

and loadings; to validate computer programs which significant.

have a nonlinear dynamic plasticity capability; and

to correlate experimental simulations with actual or One of the most important aspects of the analyses

predicted events. of brittle deformation processes is the

determination of failure which is, obviously,

The dynamic plastic deformation of some basic associated with a critical microcrack density.

structural configurations are being analyzed for However, the analytical modeling of the so-called

loadings which vary both in magnitude and region cooperative phenomena, characterized in the

of application with time. Mode approximation considered case by a disorder of the material

methods and load correlation parameters are microstructure and the interaction of many defects

hypothesized and their usefulness in predicting of random geometry, distribution and orientation

final plastic deformation is determined. The represents a serious problem. This class of

methods, based initially on a rigid, perfectly plastic problems, being inherently nondeterministic in

material model and small deformation response, nature, is seldom if ever addressed in continuum

are extended to include strain hardening, an initial mechanics. A promising strategy, to be explored

elastic response period, and large deformation in the continuation of this research program, is to

interactions. consider the application of the so-called

percolation theory. One of the two main problems

is to make a transition between the lattice and

Arizona State University continuum percolation theory and recover the damage micro-flux (Budiansky-O'Connell variable) Mechanical & Aerospace Eng $55,000 and enable mapping between the two models.

Tempe, AZ 85287 01-A The other problem is that the disorder is

88-4 introduced into the percolation model traditionally

Continuum Damage Mechanics II by a bimodal distribution which might be to

D. Kralclnovlc restrictive for real materials having a richer

hierarchy of strengths on the micro-scale.

The efforts in the first two years of this research Nevertheless, it is felt that the percolation theory

program were focused on the development of a offers a viable framework for the studies of the

micromechanically inspired continuum damage brittle deformation processes in the vicinity of the

mechanics model. Specifically, the objective was percolation thresholds (which are different that

to formulate a rigorous micro-to-macro transition those associated with transport phenomena). The

along with the conditions which must be satisfied application of the percolation theory is important

Engineering Research 2 1991
since it enables studies of estimates which the Boston University

local fluctuations of stresses (hot-spots) and Department of Chemistry $69,316

strengths (weak-links) have on the failure of the Boston, MA 02215 06-C

material. 89-3

Transport in Porous/Disordered Materials

T. Keyes Battelle Memorial Institute

Mechanics Dept $94,027 The aim of this project is the construction of

Columbus, OH 43201-2693 01-A theories of the transport processes-diffusion, fluid

90-3 flow, electromagnetic wave propagation, etc. in

An Investigation of the Effects of History materials where strong interactions or disorder

Dependent Damage In Time Dependent cause a near stoppage of the transport. Of

Fracture Mechanics special interest are materials with percolation

F. Brust thresholds, where the disorder blocks transport

altogether, and systems near a glass transition.

The demands for structural systems to perform The research is broadly based and a wide range

reliably under severe operating conditions continue of theoretical and computational techniques are

to increase. Modern energy production facilities employed. Progress along three fronts was made

experience degradation and damage because they in the past year.

operate in asevere high-temperature environment

where time dependent straining and damage may Harmonic normal mode analysis is routinely

lead to structural failures. The goal of this applied to stable solids, but is not normally

research is to study the high temperature damage considered useful for fluids. We have developed

and failure processes and to further develop a a new method for fluid dynamics, based upon

method for predicting this behavior in an effort to normal mode analysis, in which transport is

increase structural life. In particular, we focus on governed by the unstable modes of the system.

time dependent damage which occurs under The method worked extremely well for

history-dependent loading conditions, i.e. transient supercooled liquids and is now being applied to

conditions. suspensions of spheres.

The types of time dependent (creep) damage Glass ceramics are composed of irregular

considered in this program include: sustained load crystallites in a glassy matrix. The propagation of

creep, variable load creep, and variable load creep light through these disordered materials was

with thermal gradients. During the first year of this studied. The structure of the crystallites was

study, the implications of using Norton's creep law related to the properties of the scattered light in a

on various integral parameters used to completely new scheme which requires the

characterize crack tip phenomena were evaluated intensity statistics, but no knowledge of optical

as a function of time. Other constitutive laws for properties.

time dependent materials such as those of

Murakami and Ohno are being implemented into High intensity light will break chemical bonds and

the finite element code. In addition, constitutive cut material. A fairly comprehensive model of this

property data and high temperature creep crack very nonlinear process was constructed and

growth data are being obtained on stainless steel. solved, with qualitative agreement with several

These experiments will be used to verify analytical observations. Computer simulation of the

predictions and characterize time and history phenomenon was begun, with an eye to the study

dependent damage during crack nucleation and of laser-induced shock waves and to sorting out

growth. the "energy bookkeeping" -the ultimate

destinations of the laser energy.

The results from this work will be used by

practicing engineers to enhance the life of high

temperature structural systems during the design

phase.

Engineering Hesearch 3 1991
University Of California/B University Of California/LA

Dept of Electrical Engineering $93,300 Mech, Aero & Nuclear Eng Dept $78,790

& Computer Sciences 06-C School of Eng & Applied Science 01-C

Berkeley, CA 94720 90-3 Los Angeles, CA 90024-1597 89-3

Self-Generated Stochastic Heating in an RF Basic Studies of Transport Processes In

Discharge Porous Media

A. Uchtenberg, M. Ueberman I. Catton

The purpose of this project is to study electron The research covers two broad areas: 1)

heating mechanisms in radio frequency (r.f.) single-phase convection in porous media, and 2)

discharges. These discharges are used two-phase convection in porous media. The

extensively by industry for surface modification of objective of this study is to develop physical

electronic and mechanical materials. In addition to understanding of the governing phenomena and

the usual r.f. ohmic heating in the plasma interior, models for prediction of transport processes by

it has been found theoretically that stochastic theoretical and experimental means.

heating at the plasma surface plays a major role.

The stochastic electron heating arises from Non-Darcian forced convection in a porous

successive decorrelated reflections of electrons medium with anisotropic dispersion was studied.

with the oscillating sheath near the surface of the Convective heat transfer in a packed tube was

discharge. Power is also transferred directly to the modeled. It was shown that heat transfer in the

ions by acceleration in the sheaths. The efficiency thermally developing region is affected by axial

of stochastic heating depends on the detailed dispersion when the Peclet number is less than

sheath dynamics. For a low pressure discharge at 10. The effects of hydrodynamic dispersion on the

a pressure of 3 mTorr, power of 100 watts, and convection onset of a porous layer with volumetric

frequency of 13 MHz, 95% of the electron heating heating were shown to reduce the critical Rayleigh

is predicted to occur stochastically. number.

The sheath dynamics are being measured and Generalized models have been developed for

related to the predicted stochastic heating for a turbulent transport processes in highly permeable

plane parallel argon discharge. Depending on the porous media with Reynolds number greater than

details of the sheath motion, the enhancement one hundred. Improved transfer equations for the

factor of the stochastic heating can change, and solid and fluid phases were obtained by averaging

consequently so can the ratio of electron to ion the turbulent transfer equations over a

power at a given overall power level. The heterogeneous medium. A series of

measured results, together with measurements of two-dimensional turbulent flow, energy, and mass

other plasma parameters, will be used to construct transfer models was developed. The results of the

better predictive models of discharge behavior and modeling were compared with the theoretical and

parameter scaling. experimental work of others. A close connection

between closure of heat and mass transfer

Stochastic heating can be enhanced with a models, and boundary conditions is shown by

resonant helical discharge structure. This taking proper account of surface roughness within

geometry is of importance for materials processing and on the boundaries of a porous medium.

applications and is under investigation as part of

the overall program to understand plasma heating Steam injection into water flow was studied

and develop models of r.f. processing discharges. analytically and experimentally. For slow flow

(Darcy flow), the analysis yielded values of all

important parameters that compare well with the

experimental data. The importance of dispersion

to the transport of energy at the steam-water

interface was clearly demonstrated. At high steam

injection rates, the steam-bubble boundary was

shown to be unstable.

Engineerng Research 4 1991
University Of California/LA the experimental, theoretical and computational

Mech, Aero & Nuc Eng Dept $87,654 point of view. These off-equilibrium systems can

School of Eng & Applied Science 06-C display a tendency to a) form structures b) develop

Los Angeles, CA 90024-1597 89-3 a stochastic spectrum of energy and c) focus

energy. Regarding a) the formation of solitons,

Energy and Particle Transport In Random domain walls and kinks in continuous media is

Media being studied. Regarding b) the tendency of a

G. Pomranlng spectrum of acoustic motion to become wave

turbulent is being investigated and regarding c) the

The goal in this research is to develop a transduction of round into lift is being measured.

comprehensive theory of linear transport/kinetic This last phenomenon results from a self-focusing

theory in a stochastic mixture of solids and instability that concentrates energy by a factor of

immiscible fluids. Such a theory should predict the one trillion.

ensemble average and higher moments, such as

the variance, of the particle or energy density

described by the underlying transport/kinetic University of California/SD

equation. The statistics to be studied correspond Scripps Inst. of Oceanography $ 0

to N-state discrete random variables for the La Jolla, CA 92093-0402 06-C

interaction coefficients and sources, with N 90-4

denoting the number of components in the Signal Processing in Chaos

mixture. The mixing statistics to be considered H. Abarbanel

are Markovian as well as more general statistics.

We are investigating methods for modeling fluid

In the absence of time dependence and scattering, flows and plasma dynamics of relevance to energy

the theory is well developed and described by the problems when these physical phenomena exhibit

master (Uouville) equation for Markovian mixing, motion on fractal objects called strange attractors.

and by renewal equations for non-Markovian In these cases, which are quite common both in

mixing. The intent of further work is to generalize the settings indicated, and in electrical circuits and

these treatments to include both time dependence condensed matter systems, the time series have

and scattering. A further goal of this research is to continuous broadband power spectra and quite

develop approximate, but simpler, models from the irregular behavior. We are engaged in methods

comprehensive theory. In particular, a specific for identifying the space in which to work for these

goal is to formulate a renormalized systems (phase space reconstruction), methods

transport/kinetic theory of the usual nonstochastic for computing the invariants of the motions, and

form, but with effective interaction coefficients and methods for making physical models for prediction

sources to account for the stochastic nature of the in these irregular systems. These systems are

problem. Numerical comparisons of all models will inherently less predictable than familiar linear

be made against Monte Carlo simulations which systems, but their predictability is nonzero and

involve a straightforward average of solutions for may be extracted in a systematic fashion from the

a large number of physical realizations of the time traces themselves.

statistical mixing. Extensions to nonlinear kinetic

equations will also be investigated.

The work in FY91 has concentrated on methods to

extract chaotic, deterministic signals from noisy

University Of California/LA measurements. The noise may be due to

Physics Dept $115,920 environmental conditions or measurement errors

Los Angeles, CA 90024 06-C or may have been imposed on purpose to mask

90-3 the signal. With these "cleaning" tools, we will

Wave Turbulence and Self-Localization In clean up laboratory and field data for use in the

Continuous Media other parts of the signal processing effort.

S. Putterman

The fate of energy which is injected into fluids that

are far from equilibrium is being investigated from

Engineering Research 5 1991
University Of California/SD The calculation of the time that it takes to reach a

Dept of App Mech & Eng Sc $161,680 given point on a fractal is relevant for events that

La Jolla, CA 92093 06-B are triggered when an excitation or molecule or

90-3 charge reaches a designated point. Our analysis

Experimental and Theoretical Study of Fuel is based on a renormalization approach that yields

Droplets Subject to Straining Flow exact results on some deterministic fractals.

P. Libby, F. Willams Whether these methods can be applied to random

fractals is still an open question; we have applied

This research involves a combined experimental them to structures that mimic random fractals.

and theoretical effort related to the behavior of fuel

droplets. The initial experiments concerned the The rates of even the simplest diffusion-controlled

determination by photographic means of the reactions in low-dimensional systems behave very

trajectories and under the circumstances involving differently than the standard law-of-mass-action

mass loss, of the radius histories of individual descriptions and have been called "anomalous"

droplets in well defined, nonuniform laminar and indicative of "mathematical poisoning." Our

streams. The original studies involved a calculation of reaction rates is based on scaling

nonpremixed laminar flame in a counterflow arguments that lead to parameterized results.

configuration, isothermal counterflowing nitrogen Even this limited success has provided a great

streams and a vertical Poiseuille flow. The results deal of insight.

of these studies have appeared in Combustion

Science and Technology. Recently these same We continue to make progress in the (unrelated)

techniques have been applied to a droplet on a roblem of the effect of colored noise on the

vertical trajectory entering the horizontal flow from evolution of a system. We have obtained analytic

a jet with close to a top-hat velocity distribution. results for a dye laser driven by Gaussian

The purpose of this experiment was to elucidate fluctuations and also for a bistable system driven

the source of the lift found in the early by dichotomous noise.

experiments. However, the results, which are to

appear in Combustion Science and Technology

establish that conventional force laws accurately University Of California/SD

predict the droplet trajectories with the Pure & Applied Physical Science $94,000

consequence that the source of the lift measured La Jolla, CA 92093 - 06-C

in the earlier configurations remains obscure. Our 91-2

current research concerns fuel sprays in Knot Invarlants and the Thermodynamics of

counterflowing streams which result in flat Lattice Gas Automata

nonpremixed flames. Measurements of the D. Meyer

velocity distribution are underway and in due

course the droplet size and velocity will be Lattice gases, operating as cellular automata and

measured. Complementary theoretical research is amendable to massive parallelism, which simulate

underway. the Navier-Stokes equation in two and three

dimensions, were introduced in 1985 by the

University Of California/SD principal investigators (hys. Rev. Let.). Such

Department of Chemistry, 0340 $ 0 lattice gases are formed of "Boolean molecules"

La Jolla, CA 92093 06-C with discrete time, space, and velocity. Their

89-3 collision laws are designed to conserve particle

Noisy Nonlinear Systems number and momentum. Macroscopic momentum

K. Undenberg averages satisfythe incompressible Navier-Stokes

equation, in a suitable physical limit. Groups in

Transport and reactions on fractals occur in many the United States and in France are already

natural phenomena including geological processes engaged in theory, simulations, and hardware

and processes in the solid state or on surfaces. projects for lattice gas hydrodynamics. Preliminary

Much that is known comes from computer results indicate that the method is easy to

simulations. Our efforts have been directed implement (with or without boundaries), robust,

toward gaining a theoretical understanding of and reproduces known hydrodynamic phenomena.

these processes. It may eventually yield a new simulation strategy

Engineering Hesearch 6 1991
for complex turbulent flows, with many practical quite general and can be applied to a variety of

applications, physical systems with strong interaction, including

magnetized plasma.

It was proposed that the lattice gas method be

evaluated, and that modified models with higher

Reynolds numbers be studied. Two-dimensional University Of California/SD

computer models were created to run on the Dept of Physics $211,797

CRAY-XMP, the CRAY II, and on the Connection a Jolla, CA 92093 01-B

Machine II (a computer with 65,000 central 90-3

processors). These models ran at the rate of Traveling-Wave Convection In Fluid Mixtures

80,000,000, 10,000,000, and 2,000,000,000 cell C Surko

updates per second, respectively. Comparisons

with other calculational methods have been done. While some progress has been achieved recently

Athree-dimensional program has been developed in the understanding of the dynamics of free

which produced the highest Reynolds numbers convection occurring in single component fluids,

attainable with 24 bits required per cell. Flow past much less is known about the phenomenology of

a square plate has been successfully modeled by convection in fluid mixtures. Yet in realistic

this code. Summaries of this and other recent situations it is the latter that play the important work has been published in several articles in the role. Examples of interest to engineering include

August issue of Complex Systems. Lattice gas stability of double-diffusive systems, e.g. solar

methods for solving partial differential equations ponds, solidification of metal alloy casts,

appear useful and promising. Expectations of their convection in fuel droplets, and so on.

capabilities on future machines are now being

estimated. The proposed research addresses the interaction

of traveling waves with convective motion in a

binary fluid mixture. Preliminary results show that

University Of California/SD in a relatively simple experiment the behavior of

Inst for Nonlinear Science, R-002 $89,545 the system is such that on varying one or two

La Jolla, CA 92093 06-C control parameters the whole gamut of states

91-2 ranging from a laminar traveling-wave state to well

Formation of Three-Dimensional developed turbulence can be traversed.

Singularities, Regularizatlon Procedures and Specifically the experimental setup consists of an

Markovian-Multifractal Description of annular channel with a large radius. In it a waterTurbulent Flows ethanol mixture is heated from below giving rise to

E. Novikov free convection. However, under certain

conditions, in addition to this expected

The study of intermittent turbulent flows with high phenomenon, there occur traveling-waves

Reynolds number, based on development and interacting in complicated ways with the patterns

unification of different complementary approaches, driven by natural convection. The resulting

is proposed. The new recently developed method oscillatory convection seems to be prototypical of

is based on conditional averaging of equations for similar phenomena arising in many contexts,

a local characteristic of motion, which has a ranging from oceanic motion to instabilities in

mechanism of self-amplification. An exact closed liquid crystals.

equation for a conditionally averaged threedimensional vorticity field (with fixed vorticity at a The proposed research will address three related

certain point) is obtained from the Navier-Stokes topics: 1) weakly nonlinear traveling waves in one

equation. Corresponding closed equation is dimension; 2) nonlinear pulses in an annulus; and

derived for conditionally averaged vorticity gradient 3) measurement of concentration field.

in two-dimensional turbulence. Solutions of these

equations are obtained. The high order two-point

moments of vorticity and vorticity gradient are

presented. The obtained results can be verified by

laboratory and field measurements, as well as in

numerical experiments. The developed method is

Engineering Research 7 1991
University Of California/SB quantitatively the wavenumber, frequency,

Dept of Physics $125,840 amplitude, and spatial extent of these localized

Santa Barbara, CA 93106 06-C states. This information will permit a distinction

90-3 between several competing theoretical models.

Bifurcations and Patterns in Nonlinear

Dissipative Systems

G. Ahlers, D. Cannell University Of California/SB

Dept of Chemical & Nuc Eng $197,725

This project consists of experimental investigations Santa Barbara, CA 93106 01-C

of non-linear non-equilibrium fluid-mechanical 91-3

systems, with an emphasis on heat transport, Turbulence Structure and Transport

pattern formation, and bifurcation phenomena. Processes In Wavy Uquid Streams

These issues are being studied in S. Banerfee, G. Hetsroni

Rayleigh-Benard convection, using both pure and

multi-component fluids. They play an important This project is aimed at studying basic turbulence

role in such energy-related issues as crystal structure in a liquid which flows in a horizontal

growth from a melt with and without impurities, the flume. The experimental techniques used in this

catastrophic inversion of salt lakes such as the study include a three-dimensional Laser-Doppler

Dead Sea, energy production in solar ponds, and velocimeter, with a 50m measuring volume; and

various oceanographic phenomena. an oxygen bubble tracing technique with high

speed videos and flash photography.

The work utilizes computer-enhanced

shadowgraph imaging to visualize the convective The oxygen bubble technique resulted in capturing

flow patterns. The technique can detect the flow of the detailed turbulence production at the solid

field even when the convection threshold is wall and at the liquid-air interface. The details of

exceeded by only 0.1%. In parallel, the high speed-low speed velocity streaks at the

high-resolution heat-flux measurements are made wall, the coherent structures near the wall, and the

with a resolution of 0.05%. Thus, the relationship turbulent bursts were visualized and measured. It

between the pattern and the heat transport can be was found that the turbulent coherent structures

studied in great detail. reach the interface and are visualized there as

patches. These patches then have a profound

In pure fluids, we are investigating the effect on the heat and mass transfer at the

mechanisms for the convective onset. In most interface.

physical systems the flow is initiated by properties

of the experimental cell which lead to an imperfect High speed and low speed velocity streaks were

bifurcation. Recently it has been possible, also observed at the liquid-gas interface, when

however, to perfect the apparatus to a point where shear was applied on the liquid by the gas flowing

stochastic effects control the evolution of the flow. cocurrent or countercurrent to the liquid. The

coherent structures from the interface were then

Beyond the convective threshold we are interested observed to be ejected downwards.

in the evolution and stability of various convective

patterns in containers with simple sidewall Waves, which were generated by a wave

geometries. We expect that our results will help in generating machine, were observed to have a

the development of theoretical models for pattern profound effect on the frequency of ejections of

stability. the coherent structures at the wall. The effects of

the wave amplitude and wave length on the

A particularly interesting pattern-stability problem frequency and strength of the turbulent bursts are

occurs in binary-mixture convection. For certain now being analyzed.

values of the parameters of this system, there

exist spatially localized patches of travelling waves These experiments were complemented by

of convective rolls. The existence of these states numerical computations. The full Navier-Stokes

cannot be explained by the usual models with equations were solved by a pseudospectral

relaxational dynamics, but rather seem to require method to provide quantities which are difficult to

non-potential theories. We are studying obtain by flow visualization and single-point

Engineering Hesearch 8 1991
velocity measurements. The numerical Carnegie Mellon University computations were shown to capture the basic Chemical Eng Dept & Graduate $152,603

physics which is associated with the turbulence School of Indus Admin 03-A

generation due to shear. Pittsburgh, PA 15213 89-4

Thethree-dimensional Laser-Doppler velocimeter Integration of Redesign Methodologies for

was assembled, and the hardware and software Chemical Processes

were readied for the measurements. The L Blegler, . Grossmann, G. Thompson, A.

measurements with the LDV will be complemented Westerberg

by visualization by means of the oxygen bubbles

and high speed video. Process redesign, commonly known as retrofit, is

a major task in the chemical industries. However,

most systematic design strategies have been

California Institute Of developed for new process and often do not apply.

Technology This project addresses the development of

Chemical Engineering 210-41 $120,475 systematic design methodologies for the redesign

Pasadena, CA 91125 03-A of chemical processes. This integrated approach

91-3 deals with a broad range of problems in process

Modeling for Process Control redesign. Here we discuss progress in the

M. Morarl following areas:

One key difficulty which stands in the way of 1) Development of Efficient Optimization

application of many advanced control techniques Algorithms for Discrete and Continuous Variables.

in the chemical process industries is the need for Efficient decomposition strategies for nonlinear

a model to describe the dynamic behavior of the programming have been developed for large-scale

process to be controlled. The objective of this process optimization. These are currently being

research program is the development of a range of tailored to various problem types. The work also

new modeling techniques, in particular: includes the solution of several large scale

development of techniques for building physics- combinatorial optimization problems thatfrequently

based, low order, nonlinear models with physically occur in chemical engineering applications,

meaningful parameters, specifically for the purpose namely, travelling salesman, and set covering (and

of (robust) linear and nonlinear controller design; partitioning) problems. The previously devised

and development of methods for the identification algorithms have been developed on various

of linear black box models and the associated sequential and parallel computers such as the

uncertainty description suitable for robust control GRAY YMP and the Butterfly.

system design. 2) Redesign of Multicomponent Separation

At present, use of the Partial Least Squares Sequences. We have completed a study to retrofit

Technique (PLS) is explored to identify impulse well-behaved distillation problems and are now

response models for linear dynamic systems and examining the retrofit of problems involving

an associated uncertainty description which is significant nonideality in component behavior.

suitable for robust control system design. The Such problems occur commonly in waste

resulting uncertainty descriptions are given in minimization problems. Our goal is provide a

terms of orthogonal functions which in turn can be methodology for redesigning complex separation

used directly for controller synthesis. systems to reduce the levels of trace species

which must then be handed over to waste

treatment facilities. We are examining the

potential for significant reduction in the use of

energy to remove trace species by redesigning

such processes.

Engineering Research 9 1991
(3) Redesign of Energy Management Systems. these theories on experimental hardware. A

Mixed-integer nonlinear programming (MINLP) modular manipulator system consists of a set of

models have been developed for grassroots and link and joint modules of various sizes which may

the redesign problems. The unique feature of be assembled together in a desired kinematic

these models is the fact that the level of energy configuration to achieve a specific task. The

recovery and selection of matches is optimized RMMS design emphasizes modular manipulator

simultaneously without fixing temperature components having consistent mechanical and

approaches. Work is under way to develop a electrical interfaces. The uniform interfaces will

branch and bound method for finding the global allow either semi-skilled field personnel or another

optimum in these problems. Also, an LP/NLP manipulator to rapidly configure a RMMS

based branch and bound method is being manipulator to meet specific task requirements.

developed to expedite the solution of the MINLP This basic research effort will address the problem

models. Finally, the interactive program of mapping tasks into a manipulator configuration,

SYNHEAT is under development for the formulation of control algorithms for the mapped

implementation of these models. configuration, and experimental verification of the

developed ideas. Though it is not the primary

(4) Redesign for Flexibility. Controllability. and objective, we believe that building prototype

Reliability. The expected stochastic flexibility, a experimental modules for demonstrating our ideas

new measure that integrates the two operability will also contribute to the technology of modular

characteristics, has been developed. The manipulators.

proposed measure can be used to evaluate the

probability of feasible operation given uncertainties For configuring a manipulator from task

in process parameters and operational states. requirements, we will develop methodologies that

Current work includes the efficient integration of map the task requirements into a specific

multiple integrals, the handling of nonlinear manipulator. The kinematic task requirements will

process models, and bounding strategies that be used to determine the link lengths and the

require the examination of only few states. The orientation of the modules. And the dynamic task

application of the expected stochastic flexibility to requirements will be translated to obtain the sizes

bi-criterion optimization problems for retrofits is and ratings of the actuators or joints. The use of

also being considered. both rule-based expert systems and optimization

techniques will be investigated in obtaining a

(5) Optimization-Based Methods for Process solution to this problem. For effectively controlling

Identification and Control. Optimization-based modular manipulators (RMMS), a methodology for

algorithms are being developed for the control of automatically configuring a controller will be

constrained, nonlinear processes; these are also developed using model-based and/or adaptive

being used to control openloop unstable control techniques.

processes. An extended Lyapunov-based stability

theory is being developed and demonstrated. In

addition, tailored nonlinear programming University Of Chicago

algorithms are being developed for more efficient Dept of Chemistry $ 0

solution of these problems. Chicago, IL 60637 06-C

89-3

Topics in Finite-Time Thermodynamics Carnegie Mellon University R. Berry

Dept of Elec & Comp Eng $98,607

Pittsburgh, PA 15213 03-C The objective of this research is the analysis in

89-3 thermodynamic terms of the performance of

Research on a Reconfigurable Modular systems and processes subject to time or rate

Manipulator System constraints. Part of the research deals with

P. Khosla, T. Kanade developing methods for conducting analyses, such

as emerged from the introduction of a suitable

The goal of our research is to address the basic metric in the space of thermodynamic variables

theories of reconfigurable modular manipulator and the evaluation of path lengths with that metric.

systems that will culminate in the demonstration of The lengths so obtained have been shown to be

Engineerng Research 10 1991
directly related to the dissipation associated with of radiometry with emphasis on observable effects.

the path. Another piece of recent work at this Our theoretical work on nonimaging designs has

basic level just completed under this project is an led to demonstration of ultra-high flux from

attempt to introduce a variational formulation of sunlight which exceeds previous results by

irreversible heat transfer and diffusion, which is substantial factors.

intended to apply in nonlinear as well as linear

situations.

Clarkson University The other aspect of this research is the applicationf Dept of Chemical Engineering $59,000

of the general methods to the analysis of specific Potsdam, NY 13676 01-C

systems of current interest. During the initial 91-3

period of the project, the stopping of a beam of ift and Drag Forces on Droplets and

atoms by absorption and re-emission of laser light Particles In Wall-Bounded Flows

was analyzed and the entropy changes in the J. McLaughlin

process were evaluated. The reduction in entropy

of the atomic beam due to cooling and stopping is The goal of this research is to obtain quantitative

compensated a thousandfold over by the information about the lift and drag forces that act

increases in the entropy of the light due to on small droplets or particles that translate through

randomization of the phase, the polarization and shear flows. Such forces affect the motion of

especially the propagation direction. droplets or particles near a rigid wall. Thus, to

understand the deposition of droplets or particles

on the wall or their tendency to accumulate near

University Of Chicago the wall, a knowledge of such forces is important.

The Enrico Fermi Institute $147,420

Chicago, IL 60637 06-C The approach used in the research involves a

90-3 combination of analytical, numerical, and

Fundamentals and Techniques of laboratory work. The analytical approach can

Nonimaging Optics for Solar Energy provide useful asymptotic expressions for the lift

Concentration and drag forces in the regime of small Reynolds

R. Winston numbers. In most situations of practical

importance, however, the droplet or particle

Nonimaging optics departs from the methods of Reynolds numbers are not small compared to

traditional optical design to develop instead unity. As a result, direct numerical simulations of

techniques for maximizing the collecting power of the three-dimensional flow field around a sphere

concentrating elements and systems. Designs in a shear flow will provide the forces. In addition,

which exceed the concentration attainable with experimental measurements of particle velocities

focusing techniques by factors of four or more and in a vertical homogeneous shear flow apparatus

approach the theoretical limit are possible. This is will provide additional information and permit

accomplished by applying the concepts of checks of the numerical study.

Hamiltonian optics, phase space conservation,

thermodynamic arguments, and radiative transfer At present, a computer code has been developed

methods. In the early nonimaging designs the for the direct numerical simulations. The code

might edifice of aberration theory was dismantled employs a hybrid spectral-finite volume technique

and replaced by a single key idea. According to to solve the incompressible Navier-Stokes

this, maximum concentration is achieved by equation. A homogeneous flow apparatus has

ensuring that rays collected at the extreme angle been constructed and is being tested at Los

for which the concentrator is designed are Alamos National Laboratory.

redirected, after at most one reflection, to form a

caustic on the absorber. This principle proved

sufficiently elastic to accommodate most boundary

conditions in two dimensions (i.e., linear

geometry). Ideal solutions in three dimensions

have also been formulated. Our work on vector

flux has led to a reexamination of the foundations

Engineering Hesearch 11 1991
University Of Connecticut Cornell University

Dept of Mechanical Engineering $ 0 Mechanical & Aerospace Engineering $59,998

Storrs, CT 06268 01-A Ithaca, NY 14853 01-A

88-3 91-3

Micromechanical Viscoplastic Stress-Strain Chaos In Fluid-Structure Systems

Model with Grain Boundary Sliding F. Moon

E. Jordan

Integrated theoretical and experimental studies are

The goal of this research is the development and being performed to enhance the understanding of

verification of a model of the time and history nonlinear oscillations and dynamic instability

dependent viscoplastic deformation behavior of phenomena involving both fluids and solid

polycrystalline metals. Single grain behavior has structures and their coupling. The objectives are

been derived by summing postulated slip behavior to contribute to the explanation of observed

on crystallographic slip systems. Multi grain phenomena, providing insights into chaotic

behavior will be obtained by summing deformation characteristics of such coupled mechanical

occurring in different grains while accounting for systems and ultimately, to the solution of

grain interaction through a self consistent engineering design problems. This is a joint

micromechanics approach. The model will also project with Argonne National Lab.

represent grain boundary sliding through the use

of a solution recently published by T. Mura. Fluidelastic instability of loosely supported tubes,

vibrating in a tube support plate-inactive mode, is

High temperature experiments on Hastelloy-X will suspected to be one of the main causes of tube

be used to verify the model. Single crystal failure in some operating steam generators and

properties used for input to the model are currently heat exchangers. As a vehicle to understand the

being determined. Using these properties the nonlinear behavior of fluid-structure systems,

behavior of polycrystal Hastelloy-X will be fluidelastic instability of loosely supported tube

predicted and then compared with polycrystalline rows in crossflow is being studied in detail. Tube

experiments recently completed. Prediction of row with a motion-limiting stop configuration will

these tests constitute a critical test for the theory. be tested to investigate various response

characteristics and a mathematical model based

The model will not only predict the viscoplastic on the unsteady flow theory will be developed to

response of polycrystals but also will allow predict the response characteristics of this

metallurgical findings usually stated in classical fluid-structure system.

crystallographic terms to be more directly

incorporated into the model. The explicit Energy systems have had a history of dynamic

calculation of grain boundary sliding will help structural instabilities caused by fluid flow resulting

illuminate the role played by grain boundary sliding in costly component repair and replacement and

in the overall deformation during complex load loss of energy production. The understanding of

histories. Grain boundary sliding deformation dynamic characteristics, including periodic

plays an important role in material damage and oscillations, random vibration, and chaotic motion,

the model should be useful in life prediction under will impact the design and reliability of these

complex variable temperature conditions. systems in both the near and long term. In

addition, fluid-structure systems are classical

At present, the single crystal model is available examples of autonomous systems that can exhibit

and the self consistent model without grain chaotic behavior. Knowledge of the fluid-structure

boundary sliding has been derived and is being systems may provide some insights into the

programmed. chaotic behavior of other energy system

components.

This work is being done with the cooperation of

Engineering Science Software, Inc. working under

a related contract. Single crystal specimens have

been provided by Pratt and Whitney, Inc.

Engineering Research 12 1991
Cornell University Dartmouth College

Sibley School of Mech & Aero Eng $102,000 Thayer School of Engineering $140,000

Ithaca, NY 14853 01-C Hanover, NH 03755 06-C

91-3 91-2

Experiments In Turbulent Mixing Mixing and Settling in Continuous Metal

Z. Warhaft Production

H. Richter

This project is concerned with experimental

studies of scalar mixing in fully developed For reasons of both energy conservation and

turbulent flows, a subject relevant to our environmental protection, tonnage oxygen has

understanding of chemical reactions, combustion become an essential component in many ferrous

and environmental pollution. Mixing in both and nonferrous smelting and refining operations.

homogeneous and inhomogeneous turbulence, Innovative reactors such as the QSL converter for

with and without the effects of buoyancy is being direct lead bullion production are also suitable for

examined. direct coppermaking and a modification of the

reactor is also very attractive for steelmaking.

The first experiment concerns scalar dispersion

and mixing in a jet. This is studied using a novel Oxygen and fuel are bottom-injected into the

method of introducing a scalar (temperature) into molten bath of these essentially horizontal reactors

an air jet by means of placing thin heated wire in controlled rates required for heating, physical

rings, axisymmetrically, downstream from the jet mixing and chemical reaction purposes. Sufficient

origin. The diameter of the rings and their location turbulence is generated to maximize heat and

from the jet is varied so that the effect of initial mass transfer rates. However, such bath

conditions on the subsequent evolution of the turbulence is opposite to the process requirement

scalar mixing can be studied. The placing of a for continuous countercurrent flow of liquids at

thin wire ring in a jet is analogous to placing a line specific temperature, compositional and oxygen

source in homogeneous turbulence, a subject that potential gradients. The powerful stirring effected

has received much attention. We can anticipate by submerged gas injection is therefore judiciously

that the thermal field will be more complex than localized so as to provide adequately calm settling

that of a line source since as the flow evolves the zones between the active turbulence zones in a

thermal field from one side of the flow will begin to staged mixer-settler.

mix with that from the other side. This does not

occur with a line source in grid turbulence. So far The research objectives of the work are to learn

as we can determine there has been no previous about the behavior of gas and particulate matter in

study of a heated ring source in a jet. The effects turbulent liquids, the nature and paths of liquids

of two scalar mixing is also being studied by and particulate entrainment into the plumes, and

adding a second ring. Preliminary findings show separation phenomena including travel to and

unexpected results concerning the evolution of the behavior in the settling zones. Such knowledge is

segregation and cross-correlation coefficients. of fundamental value in designing reactors for

continuous, direct metalmaking.

The second main experiment is concerned with

scalar mixing in stably stratified decaying grid The new information will predict bath mixing, heat

generated turbulence. A temperature (density) and mass transfer and settling parameters under

gradient is formed at the entrance to the plenum the variety of operating conditions which will

chamber of the wind tunnel and then the flow is prevail in continuous, direct metalmaking oxygen

passed through a turbulence generating grid. reactors of the future. Therefore, it is proposed to

Single and multiple line source dispersion study gas injection through submerged injectors,

experiments on mixing across sharp temperature and also particulate addition from above, into a

steps, with and without buoyancy, are being liquid bath consisting of two immiscible layers of

attempted. liquids having roughly the same viscosities as slag

and matte or metal and with roughly comparable

density ratios. This work will be initiated in

September, 1991.

Engineering Research 13 1991
Dartmouth College Duke University

Thayer School of Engineering $114,879 Mech Eng & Mat'ls Sci Dept $60,000

Hanover, NH 03755 01-C Durham, NC 27706 01-C

89-3 90-3

Two Phase Potential Flow Analytical and Experimental Study of

G. Walls Instabilities in Buoyancy-Driven Convection

in Porous Media

The objective is to develop theorems for two- J. Georgiadis

phase potential flow analogous to those existing

for single phase flow. The mission of this research project is the study of

thermal instability phenomena associated with

Using one function, the "exertia," which describes natural convection in two classes of fully-saturated

the external fluid inertia due to relative motion of porous media systems: (1) porous media

suspended particles, it has been possible to derive saturated with pure fluids, and (2) porous media

the average stress tensor, kinetic energy, overall saturated with binary fluids. Our primary

momentum flux tensor and equations of motion for objectives are: (1) the delineation of the various

uniform systems of particles and the effective stability domains for the convective flows and an

Bernoulli equation for the fluid flowing through a exploration of the convective states after the onset

stationary array of particles. of secondary instabilities, (2) the development of

novel experimental techniques for high precision

Recent developments include more general measurements and determining the flow patterns

descriptions of the mean particle stresses and the in porous media, and (3) the validation of

averaged Bernoulli equation for the fluid when macroscopic governing equations for natural

both phases have a general motion. Links have convection in porous media.

also been established between this approach and

Guerst's variational methods including the Emphasis is put on the first two objectives. An

derivation of equations of motion for each phase, experimental investigation of the onset of natural

it being possible for the dispersed phase to be convection in a porous medium with internal heat

compressible. generation is initiated. The potential of Magnetic

Resonance Imaging (MRI) techniques in

The equations of motion for each phase have also visualizing low-speed flows in porous media is

been expressed in terms of a mutual "interfacial also investigated. We will explore ways of

pressure tensor" that is related to both the average obtaining quantitative information on interstitial

stress in the dispersed phase and the net force on velocity profiles by using a combination of spin

the continuous phase. This interfacial pressure tagging and spatial encoding MRI processes.

tensor is also closely coupled to the Reynolds Direct numerical simulation and stability analysis of

stresses in the continuous phase. the pertinent convective states will be performed in

conjunction with the experimental component of

The exertia and added-mass coefficients have this investigation.

been computed for various geometrical

arrangements of spheres, both in an infinite array

and in tubes. Comparable measurements were Engineering Science Software

made by measuring the natural frequency of Smithfield, Rl 02917 $0

oscillation of such arrays in water. Future 01-A

experiments are planned in which more properties, A Micromehanical Viscoplastic Stress- 88-3

such as pressure fluctuations, are measured. Strain Model with Grain Boundary Sliding

K. Walker

Theoretical and experimental efforts are underway

to obtain realistic interphase forces including the The aim of the project is to develop a viscoplastic

effects of viscosity and drag. Computations show constitutive model, with accompanying FORTRAN

that the effects of pressure gradient, added mass, software, to model the deformation behavior of

phase change and drag do not add linearly except polycrystalline metals comprised of an aggregate

at low Reynolds numbers. This has implications of fcc single crystal grains whose crystallographic

for the transient response and stability of fluidized axes are oriented at random. The single crystal

Engineering Research 14 1991
grains are assumed to be spherical and are Previous efforts have shown that the minimum

modeled with an anisotropic viscoplastic theory heat flux can be brought to about 75% of the

based on crystallographic slip along the octahedral maximum flux for highly subcooled Freon-113

and cube slip directions of the fcc metal. The flowing over an electrically-heated cylindrical

overall response of the polycrystalline aggregate is heater. An analysis in which the peak and

assumed to be isotropic and is deduced from the minimum heat fluxes predicted by correlations of

single crystal response by means of a experimental data were equated showed that

self-consistent method. The effect of grain higher levels of subcooling in Freon-113 might

boundary sliding between the grains is being allow the transition region to be avoided altogether

modeled in the self-consistent formulation to with only moderate increases in liquid velocity.

assess the importance of including this mechanism Our apparatus is now being re-designed to

in the overall response of the polycrystalline operate at moderate pressures so that

material. substantially higher levels of subcooling will be

achievable. The test section will also be

Experimental tests on single crystal specimens of reconfigured so that about a 50% increase in

the superalloy Hastelloy-X are being run at the velocity will also be possible.

University of Connecticut to determine the material

constants in the single crystal constitutive model. An effort to model the film boiling process around

The overall response of the self-consistent model a cylindrical heater is well underway. A

of the polycrystalline aggregate will then be generalized solution that includes all of the

theoretically determined and compared with possible effects on the development of a vapor

experimental results from isotropic specimens of layer around the heater has been achieved up to

polycrystalline Hastelloy-X. the point where the vapor layer separates from the

heater surface. The influence of variable

The FORTRAN software will allow metallurgical properties is included and has a substantial effect

and micromechanical work reported in the on how the vapor layer develops around the

literature to be easily embedded in a constitutive heater. A technique for matching a wake solution

(stress-strain) framework for analyzing the overall to the boundary-layer-like solution over the front

deformation response of polycrystalline metal part of the heater has been developed and the

aggregates under thermomechanical loading resulting equations are now being solved.

conditions.

The intent of this part of the research is to yield a

This is a joint program with the University of method that can be used to study the influence of

Connecticut under Professor Jordan. liquid-solid contact and highly-turbulent frothy flow

near the heater surface on the shape of the film

University Of Houston boiling curve. If the transition boiling region is to

Dept of Mechanical Engineering $36,008 be avoided, then the film boiling prediction must

Houston, TX 77204-4792 01-B be valid down to heater temperatures typical of the

91-1 critical heat flux. This analysis will allow the

High Flux Film and Transition Boiling determination of the influence of various system

L Witte parameters on the shape of the film boiling curve.

This project has focussed on the potential for

altering the boiling curve to avoid the unstable Idaho National Engineering Lab

transition boiling region through the effects of high Biotechnology and Geosciences $104,000

subcooling and high velocity. Both experimental Idaho Falls, ID 83415-2210 06-A

and analytical approaches have been taken, with 89-3

recent efforts concentrating on developing an Three Phase System Modelling

analytical method by which the influences of high G. Andrews

subcooling and velocity on film boiling and

pseudo-film boiling in the transition region could Many unit operations in environmental

be predicted. engineering, including biological wastewater

treatment and flotation (used to remove colloids

from wastewater and sulfur from coal), involve

tngineering Research 15 1991
bubbles rising through water containing both This project is one of six projects comprising a

surface-active materials and suspended particles. collaborative research program with the

There is no general theory to predict the Massachusetts Institute of Technology.

hydrodynamics near millimeter-sized bubbles in

this situation, which makes it difficult to predict the

gas/liquid mass transfer rate (in biological Idaho National Engineering Lab

wastewater treatment) or the number of particles Energy & Systems Tech Group $220,000

that strike the bubble (in flotation). This task will Idaho Falls, ID 83415 06-A

develop a mathematical model of the situation on 90-3

the upper surface of the bubble where most mass Modeling of Thermal Plasma Processes

transfer and particle capture occurs. The model J. Ramshaw, C. Chang

will be based on integral boundary layer theory for

the hydrodynamics and the transport of surfactant Optimization of thermal plasma processing

to and from the interface, and will include the techniques requires a better understanding of the

effect of adsorbed surfactant on the force balance space- and time-resolved flow and temperature

at the bubble interface, distributions in the plasma plume and of the

interactions between the plasma and injected The results will be compared with experiments particles. The present research is directed toward

designed to measure the particle capture rate as the development of a comprehensive

a function of surfactant concentration (i.e., computational model capable of providing such

interfacial tension) and particle concentration. information. The model is embodied in the LAVA

Particle capture rate is measured because it is a computer code for two- or three-dimensional

very sensitive indicator of bubble interface motion. transient or steady state thermal plasma

simulations. The plasma is represented as a

multicomponent ideal gas governed by the Idaho National Engineering Lab transient compressible Navier-Stokes equations.

Applied Optics $290,000 Multicomponent diffusion is calculated by a

Idaho Falls, ID 83415 06-A self-consistent effective binary diffusion

90-3 approximation, including ambipolar diffusion of

In-Flight Measurement of the Temperature of charged species. Subgrid-scale and k-epsilon

Small, High Velocity Particles turbulence models are included. Dissociation,

J. Fincke ionization, and plasma chemistry are treated by

means of general kinetic and equilibrium chemistry

Knowledge of in-flight particle parameters is routines. Discrete particles interacting with the

fundamental to understanding particle/plasma plasma are represented by a stochastic particle

interactions in the physical and/or chemical model which allows for distributions in particle

processing of fine powders. A measurement sizes, shapes, temperatures, etc. Departures from

technique for simultaneously obtaining particle local thermodynamic equilibrium (LTE) are

size, velocity and temperature has been accounted for by a two-temperature model which

developed. Particle size and velocity are obtained permits the electon and heavy-particle

from a dual color combination laser Doppler temperatures to differ. Nonequilibrium populations

velocimeter (LDV) and laser particle sizing system. of excited levels will be treated as separate

The LDV system consists of a crossed beam chemical species, with collisional and radiative

technique while particle size is determined from transitions between levels modeled as kinetic

the absolute magnitude of scattered laser light, chemical rate processes. Applications of the

The particle temperature is determined by a two model to date include simulations of plasma jets

color pyrometer technique. The spatial resolution and plasma spraying.

is better than 1mm3 and allows the distribution of

particle size, velocity and temperature to be

mapped over laboratory scale flow fields. The

influence of particle size, injection rate, torch

power, etc., are currently being examined in typical

flow fields.

Engineering Hesearch 16 1991
Idaho National Engineering Lab This project is carried out in collaboration with

Materials Technology Group $410,000 Professors Parks and McClintock at MIT.

Idaho Falls, ID 83415-2218 01-A

90-3 Idaho National Engineering Lab

Elastic-Plastic Fracture Analysis Emphasis Materials Technology Group $505,000

on Surface Flaws Idaho Falls, ID 83415 03-A

W. Reuter, W. Uoyd, J. Epsteln 90-3

Intelligent Control of Thermal Processes

The objective is to improve design and analytical H. Smartt, J. Johnson

techniques for predicting the integrity of flawed

structural components. The research is primarily This project addresses intelligent control of thermal

experimental, with analytical evaluation guiding the processes as applied to materials processing.

direction of experimental testing. Tests are being Intelligent control is defined as the combined

conducted on a material (a modified ASTM A-710) application of process modeling, sensing, artificial

exhibiting a range of fracture toughness but intelligence, and control theory to process control.

essentially constant yield and ultimate tensile The intent of intelligent control is to produce a

strength. As test temperature increases, the good product without relying on post-process

specimen configuration-fracture toughness inspection and statistical quality control

relationship complies initially with requirements for procedures. The gas metal arc welding process is

linear elastic-fracture mechanics and extends used as a model system; considerable

beyond the range of a J-controlled field. fundamental information on the process has been

Presently, compact tension and bend specimens developed at INEL and MIT during the past six

are being used to develop state-of-the-art years. Research is being conducted on an

fracture mechanics data for comparisons with data extension of the fundamental process physics,

developed from specimens containing surface application of neural network-like dynamic

cracks. controllers and signal/image processors, and

development of noncontact sensing techniques.

These comparisons are presently underway for 6.4 Tasks include physics of nonlinear aspects of

and 12.7 mm thick surface- flawed specimens. molten metal droplet formation, transfer, and

Metallographic techniques are being used to substrate thermal interaction; understanding the

measure crack tip opening displacement and relationship of neural network structure and

remaining ligament configurations for comparison associated learning algorithm to model

with analytical models. Other techniques including development and learning dynamics in neural

microphotography and replicating of the crack tip networks with the objective of obtaining a

region to complement the above measurements fundamental understanding of network transfer

are being used to identify limits and capabilities of functions; and advanced sensing, including the

each technique. Moire interferometry techniques propagation and interaction of ultrasound in

are being used to evaluate and quantify the metallic solid and liquid media.

deformation in the crack region. These data are

being used to experimentally measure J and This project is part of a collaborative research

CTOD for standard (CT and SENB) specimens as program with the MIT.

well as for specimens containing surface cracks.

The above tests have been supplemented by

using specimens fabricated from aluminum (dimple Idaho National Engineering Lab

rupture only) and titanium. The titanium Nondestructive Mat'ls Charact Group $190,000

specimens are being used to study the fracture Idaho Falls, ID 83415-2209 03-B

behavior and the ability of existing models to 90-3

predict failure for weldments. Moire interferometry Nondestructive Evaulation of

techniques are being used to study the local Superconductors

constitutive behavior and the fracture process at K. Telschow

the crack tip region of the weldment. Automated -

techniques are being developed to obtain, store The purpose of this task is to perform fundamental

and analyze the moire data. research which will lead to the development and

Engineering Hesearch 17 1991
application of new nondestructive evaluation layers, and (4) control and coordination of large

(NDE) techniques and devices for the scale systems based on (probabilistic)

characterization of high-temperature multimodeling.

superconducting materials. In the near future,

application of these new superconductors will Some of the specific mathematical models that are

require NDE methods for evaluating the properties being used in this context are Markov chains,

of wires, tapes, and coatings. Microstructural and, stochastic teams, and deterministic and stochastic

particularly, superconducting properties, must be teams, and dynamic games, each one under a

measured noninvasively in a manner capable of number of different information patterns.

providing spatial information so that fabrication

processes can be optimized. Although the Following this first phase, research is being

fabrication of these ceramic materials is being directed towards developing a new framework, to

pursued by many different techniques at present, allow for distributed and interactive model building

there is enough similarity in the different and control, where both structural and decision

superconducting materials and the fabricated making hierarchies evolve over time. A unique

forms to begin research into NDE measurement characteristic of this approach is that the two

techniques. A noncontacting AC induced current independent tasks - modeling and control -

measurement technique has been developed treated heretofore independently, will now be

which can determine critical currents on a local designed to evolve in parallel and complementarily

scale with resolution down to 1 mm. This to each other.

technique can be used in conjunction with DC

transport currents to determine spatial variations in

critical current dissipation. It also can be used University Of Illinois

alone to induce the critical state and full field Dept of Chemical Engineering $108,337

penetration into the sample directly under the Urbana, IL 61801 01-C

probe. With the aid of the "critical state" model for 89-3

flux pinning, local critical current values can be Gas-Liquid Flow In Pipelines

determined without any connections to the sample. T. Hanratty

These measurements are being applied to coating

and wire geometries and the results are being Research is being conducted to obtain a better

correlated with material microstructure information understanding of gas-liquid flow in horizontal and

Nonlinear flux trapping signals are being recorded vertical pipelines. The goals are (1) to model slug

with a new pulsed probe extension of this flow and to predict when slugging will exist in

technique. horizontal gas-liquid flows, (2) to obtain improved

predictive methods for horizontal and vertical

annular flows, and (3) to develop models for the

University Of Illinois dispersion and deposition of drops and particles in

Coordinated Science Laboratory $122,000 a turbulent flow. Vertical flow experiments are

Urbana, IL 61801 03-A conducted in pipelines with diameters of 3/4 in., 1

91-3 1/2 in., and 2 1/4 in. The horizontal flow facility

Model Building, Control and Optimization of has 1,2,3,4 in. pipelines mounted on a specifically

Large Scale Systems designed platform whose angle can be controlled

T. Basar, P. Kokotovic to within 0.01 degree. Droplet motion in turbulent

flows is studied in a vertical 2 in. pipeline and in a

This research program aims at a comprehensive supercomputer simulation for turbulent flow in a

study of some fundamental issues that arise in the channel. A specifically designed facility that

modeling, control and coordination of deterministic creates stationary slugs in a pipeline is also

and stochastic large scale systems. The research available.

plan during the first phase has been to extend the

relevant existing theories and methodologies in Considerable progress has been made in

novel directions, covering areas such as (1) model developing a new mathematical framework for

simplification through decomposition and describing particle motion in horizontal turbulent

aggregation, (2) temporal and spatial hierarchies, fields, where gravitational settling can be

(3) goal-oriented hierarchies and multiple decision important. This is being applied to understand

Engineering Research 18 1991
droplet distribution in gas-liquid annular flows and b) Forced convection behavior of viscoelastic

sediment transport. A Lagrangian framework is fluids in laminar flow through rectangular

used. The central problem, then becomes the channels.

description of the behavior of drops or particles

originating from a source on the wall. To aid in To date the following results have been found:

modelling gas-liquid annular flows, optical

techniques are being used to study droplet a) High concentrations of the aqueous

configurations and drop size. hydroxyethyl cellulose solutions yield higher

values of the boiling heat flux than found with

A central problem in understanding the behavior of deionized water when compared at the same

particles in a turbulent fluid is the prediction of the wall-to-fluid temperature difference. In

effect of flow inhomogeneities. This is being contrast, aqueous polyacrylamide solutions

studied both in computer and laboratory yield lower values of boiling heat flux than

experiments. Of particular interest are the found with deionized water when compared

discovery of a mechanism by which particles are at the same wall-to-fluid temperature. A

trapped at the wall and of a relation of particle new series of measurements with another

impaction on a wall to eddy structure. cellulose (CMC) is underway to determine if

this family of polymers has special boiling

In previous work necessary conditions for the properties. Detailed rheological properties

existence of slugs were developed that viewed the are being measured to provide some insight

front of a slug as a hydraulic jump and the tail as into the boiling behavior.

a Benjamin bubble. These are now being tested

in special experiments which create stationary b) The forced convection heat transfer

slugs in a downward inclined pipeline, performance of viscoelastic fluids in laminar

flow through rectangular channels is

A comprehensive study of droplet distributions for considerably higher than predicted for purely

gas-liquid annular flow in a 4 inch pipeline was viscous fluids, although the measured friction

completed. These gave the unanticipated result factor is in good agreement with the value

that a secondary flow can be initiated in the gas predicted by the purely viscous analysis.

flow because of the presence of drops. Measurements of the dynamic properties

including phase shift under oscillatory

University Of Illinois At Chicago condition are shown to be related to observed

Energy Resources Center $70,070 heat transfer behavior.

Chicago, IL 60680 01-B

91-2

Momentum and Heat Transfer Processes In Jet Propulsion Laboratory

Viscoelastic Fluids Pasadena, CA 91109 $0

J. Hartnett 03-C

Neural Learning Formalisms for Global 89-3

The goal of the research is to study the fluid Manipulator Redundancy Resolution

mechanical and heat transfer behavior of Problems in Unstructured Environments

viscoelastic aqueous polymer solutions. The J. Barhen

ultimate objective is to provide a basis for

predicting the performance of such fluids. At the In many applications the robotic arm needs to

present time, two basic investigations are have sufficient maneuverability so as to carry out

underway: its tasks in the presence of obstacles and in

constricted locations. One way to achieve that is

a) Pool boiling behavior of aqueous solutions of to endow the arm with an extra degree of freedom.

several high molecular weight polymers, While mechanically that is easy to implement, say

including hydroxyethyl cellulose, by the addition of an extra joint, the mathematical

carboxymethyl cullulose (CMC) and problem associated with the guidance of the arm

polyacrylamide and a comparison with pool becomes very difficult. The reason for that is that

boiling performance of deionized water. with the conventional six-degree-of-freedom

system the relationship between the location and

Engineering Hesearch 19 1991
orientation of the arm's joints and the location of methods developed to various possible

the arm's tip is uniquely determined, while the truncations. In addition, a model to handle the

redundancy accompanying additional degrees of collision of particles - that are found to occur very

freedom yields an infinity of such relationships. frequently - is being derived.

The proposed research will address the resolution

of the mathematical problems arising in the latter

case. Robert H. Kraichnan, Inc.

303 Potrillo Drive $61,694 Specifically, neural networks will be used to permit Los Alamos, NM 87544 01-C

the robot arm to learn which of the possible 90-3

motions of the arm are the most appropriate under Turbulence Theory and Reduced

given conditions. These networks are really Hydrodynamic Description

models of the way we think, learn, and remember. R. Krachnan

Those functions are represented by a set of

differential equations with many possible solutions, Turbulent flow is omnipresent in geophysics and in

each of which is accessible from well defined initial energy-producing devices. Atmospheric turbulent

conditions. In effect the individual solutions serve transport plays an essential role in the movement

to encode a learned response to a given stimulus. of heat, moisture, and pollutants. Turbulent flows

typically contain an enormous amount of information. Both for practicable computation and for

Johns Hopkins University physical understanding, it is necessary to extract

Mechanical Engineering Dept $69,682 essential information in compact form. This proBaltimore, MD 21218 01-C ject explores two recent approaches to economical

89-3 and meaningful description of turbulence. One is

Numerical and Physical Modeling of Bubbly a systematic scheme for reducing the number of

Flow Phenomena degrees of freedom ("decimation"). The other,

A. Prosperetti developed only during the past year, is a method

for distorting velocity fields with simple statistics

The ultimate purpose of this study is to put the into self-consistently determined approximations

widely used engineering averaged-equations of actual turbulent velocity fields ("mapping

models of multi-phase flows on a firmer basis by closure"). Unlike traditional analytical methods for

comparing their results with those of direct turbulence, mapping closure yields full probability

numerical simulations. The first task is the distributions of velocity fields and contaminants

development of suitable numerical techniques for carried by the turbulence. In particular, it can give

the description of the motion of particles and meaningful estimates of the likelihood of extreme

bubbles in a fluid. events. Currently, the application of mapping

closure to the transport of passive contaminants

Two different methods have been developed for by three-dimensional random velocity fields is

this purpose. Both the case of potential flow and being investigated. Previous work has shown the

high-Reynolds-number flow have been success of the method for predicting the

addressed. The situations investigated include the probability distribution of velocity in Burgers' model

small-amplitude oscillatory flow for which the of turbulence.

added mass, viscous, and Basset force

coefficients have been calculated. The first one is

fitted very well by Zuber's cell-theory result, and Lawrence Berkeley Laboratory

simple analytical expressions have been derived Accelerator & Fusion Res Div $125,000

for the other two. Other problems are the University of California 06-C

convective transport of spheres in a converging- Berkeley, CA 94720 90-3

diverging nozzle and the buoyant rise of a cloud of

spheres. Studies in Nonlinear Dynamics

A. Kaufman, R. Lttlejohn Currently, the efforts are directed to reducing the

computing time needed for the simulations. This This project involves studies of fundamental

requires a careful study of the sensitivity of the properties of nonlinear dynamical systems which

Engineering Hesearch 20 1991
arise in physical situations of importance to energy adequately controlled by a micro-processor

research. A major area of theoretical investigation system. For automobile engines this offers the

concerns several different aspects of wave prospect of efficient and clean operation

systems. Special focus is given to wave packets; associated with relatively low exhaust temperature,

the role played by the Maslov index in devoid of the problems of knock and

multidimensional wave problems; the occurrence cycle-to-cycle variation and meeting practically all

of Berry's phase in wave and other dynamical air pollutant emission requirements. The major

systems; the role of periodic orbits in the spectrum technological constraints imposed upon the

of chaotic wave systems; and linear mode automotive industry, the octane number and the

conversion. Recent progress includes the catalytic converter, could be therefore eliminated.

exploration of the relation between the Maslov Means to accomplish this task involve the

index and the phase space structures of nonlinear utilization of a pulsed jet combustion system

Hamiltonian dynamical systems; new methods of combined with prompt product recirculation,

computing the Maslov index, both for finding wave according to concepts developed on this project.

functions and eigenvalues; elucidation of the Major laboratory apparatus for our studies consists

relationship between the Bohr-Sommerfeld and of a cylindrical vessel with unobstructed optical

Maslov phases and the recently discovered insight, and a shock tube providing about 20 msec

"Berry's phase"; a discovery of Berry's phase in of test time at an elevated pressure (up to 50

the adiabatic motion of charged particles in atms) and high temperature (around 1000K),

magnetic fields; a study of complex rays in eikonal commensurate with conditions existing during

theory, and their relation to complex Lagrangian combustion in engines. Its use is associated with

manifolds, Stokes' lines and turning points; a laser-powered optical instruments, including in

numerical exploration of the role of periodic orbits particular apparatus for megacycle-frequency

in the spectrum of a chaotic wave system; and the schlieren cinematography and laser induced

first treatment of mode conversion phenomena for fluorescence imagery. In addition to experimental

multidimensional systems, involving novel work, included in the program are numerical

"reduction" techniques. Emphasis is given to the modeling studies of the fluid mechanic,

use of a phase space approach to wave thermodynamic, and chemico-kinetic phenomena

phenomena in all these applications. A second influencing the processes of ignition and

area of investigation concerns action principles, combustion in engines.

which are being used to imbed single-particle Lie

transform perturbation methods in collective

models, such as Vlasov-Maxwell systems. Lovelace Medical Foundation

Nonlinear phenomena (e.g., ponderomotive forces) Bioengineering Research $50,660

are thus dealt with systematically. Albuquerque, NM 87108 01-C

91-2

Two-Phase Flow Measurements by NMR Lawrence Berkeley Laboratory E Fukushima, S. Altobeli, A. Caprihan

Applied Science Division $100,000

University of California 06-B This project will develop nuclear magnetic

Berkeley, CA 94720 91-1 resonance (NMR) methods to measure velocity

and concentration distributions of both phases in

Controlled Combustion two-phase flows. Systems to be studied include

A. Oppenheim concentrated suspension flows in circular tubes,

solid-liquid flows in Couette geometries as well as

The principal objective of this project is to provide to gas-liquid and liquid-liquid flows.

a fundamental background for the development of

controlled combustion systems. Of particular One approach to velocity measurements is to

interest in this respect are essential improvements measure an incremental spatial displacement of

of combustors for prime movers so that they will nuclear spins that are noninvasively tagged

provide service not only as power sources, to whereas another is to measure the phase

which they are solely relegated today, but also as evolution of the nuclear spin precession which

modern high-tech chemical reactors, where depends on the translational velocity. The first

process instabilities and pollutant formation are method is best suited for flows in uniform

Engineering Research 21 1991
geometries such as pipe flows whereas the University Of Maryland

second, more complex method, is better suited for Dept of Electrical Engineering $81,745

non-uniform cases such as for nonneutrally College Park, MD 20742 06-C

buoyant flows in a Couette geometry. 88-4

Mathematical Models of Hysteresis In order to improve the capabilities of the i Mayergoyz

apparatus to make rapid measurements, a major

instrumentation upgrade is being performed during This research is concerned with the development

summer and fall of 1991. This consists in a new of mathematical models of hysteresis. These

operating system and computer, hardware models are phenomenological in nature and, for

improvements to the rf electronics, and a shielded this reason, they can be applied to the description

magnetic field gradient coil system. The studies of of hysteresis regardless of its physical origin.

concentrated suspensions in pipe flow for velocity

and concentration distributions is complete except The main research objectives of the ongoing

for measurements of particle velocities. The next research can be briefly summarized as follows:

major experimental emphasis will be on liquid- development of new generalized Preisach models

solid flows in an asymmetric Couette device. of scalar hysteresis, study of new Preisach models

of vector hysteresis, software implementation of

This is a joint project with Sandia National Lab. the Preisach hysteresis models, extensive

experimental testing and verification of hysteresis

models, development of new techniques for the

University Of Maryland calculation of magnetic fields and eddy currents in

Dept of Mechanical Engineering $51,999 media with hysteresis, application of Preisach type

College Park, MD 20742 03-C models to the description of superconducting

90-3 hysteresis and evaluation of hysteretic losses in

The Use of Stereo Optical Flow Fields in the hard superconductors. It is hoped that, as a result

Determination of Three-Dimensional Motion of the ongoing research, the foundations of

and Stereo Correspondence comprehensive theory of mathematical models of

J. Duncan hysteresis will be established.

In this study, the optical flow fields in the left and

right image sequences of a stereo camera pair are University Of Maryland

being used to determine the three-dimensional Electrical Engineering Department $79,135

motion and position of the camera platform relative Baltimore MD 21228 03-B

to objects in the field of view. A method has been 89-3

found that uses a robust statistically based Pulse Propagation in Inhomogeneous Optical

calculation to determine the camera motion and Fibers

feature points in one image that correspond to C Menyuk

given features in the other image (stereo

correspondence). This method is presently being Our research, which was originally focused on light

evaluated experimentally. Preliminary results from propagation in inhomogeneous optical fibers, has

tests with synthetic images show that the method broadened in scope to include studies of solid

produces accurate results when there are not too state rib waveguides and Y-junctions which are

many points without stereo matches in the two used to guide and switch light. The work on

images, when all the points in the left and right optical fibers is divided into two research projects.

images belong to objects with the same three- The first project concerns long-distance

dimensional motion relative to the cameras, when communication using solitons. We have been

the noise levels are less than about 10%, and particularly concerned with the effects of randomly

when the cameras are accurately mounted in a varying birefringence, and we have shown that its

parallel configuration. Techniques are currently effect is benign. From the basic equations, we

being developed to extend the method to were able to show from an appropriate ordering

situations where the four conditions mentioned expansion that the nonlinear Schrodinger equation

above are not met. is the lowest order equation, and, hence, we

expect its behavior to dominate the soliton

Lngineering Research 22 1991
evolution even in a highly birefringent fiber, as joint reaction forces can be computed on a

long as the birefringence is rapidly varying. We link-by-link basis. Furthermore, a design

have also studied optical fiber soliton switches methodology has been developed for the

based on trapping and dragging. To do the work determination of gear ratios. It is shown that

on optical fibers, we have collaborated with kinematic isotropy and optimal accelerationscientists at AT&T Bell Laboratories. The first capacity can be achieved through proper

solid state project was to find the effect of a choice of gearings.

quantum well on the propagation characteristics of

a rib waveguide. Using a planar guide as 3) Criteria for differentiating transmission

reference, we were able to show that the effect of characteristics in tendon-driven manipulators

the real geometry is qualitatively small but can have been established. It is shown that the

have a significant quantitative effect. The second effect of tendon routing can be characterized

solid-state project is to determine the effect of by a condition number and the direction of

dry-etching on the mode-holding characteristics of the homogeneous solution. In addition, an

the device. As a consequence of the etching, the efficient technique for resolving redundant

height at which the junction splits can vary. We actuator torques has been developed. The

showed that the rounding has a very small effect, technique offers an opportunity for realtime

in contrast to blunting which occurs when the computed-torque control of such

materials are chemically wet etched. manipulators.

4) In order to gain better understanding of

University Of Maryland three-DOF, four-jointed wrist mechanisms,

Dept of Mechanical Engineering $55,000 trajectories of bevel planetary gear trains are

& Systems Research Center 03-C analyzed in detail, workspace and singularity

College Park, MD 20742 88-3 problems are studied. Design criteria for full

workspace and maximal four-root region

The Creation of Multi-Degree-of-Freedom have been established.

Mechanisms for Robotic Applications

L Tsal University Of Maryland

This research is concerned with one of the most Dept of Mechanical Engineering $127,000

difficult stages of mechanical design. The main College Park, MD 20742 01-C

objective is to develop systematic methodologies 91-3

for creation of multi-Degree-Of-Freedom (DOF) Lagranglan Analysis of Contaminant

robotic mechanisms. However, the analysis and Dispersal in Bounded Turbulent Shear Flows

control of such mechanisms have also been J. Wallace, P. Bernard, J. Balint

studied. We discuss progress in the following

areas. The objective of this project is to study the

physical processes associated with turbulent

1) An innovative concept for controlling gear scalar transport in shear flows with a view towards

backlash has been conceived. The concept developing novel techniques for predicting

utilizes redundant unidirectional drives to contaminant dispersal in the environment. A

ensure positive coupling of gear meshes. closely coordinated experimental and theoretical

Then, a systematic methodology for the research program is followed combining wind

creation of such mechanisms has been tunnel experiments using hot-wire probes, smoke

developed. The concept has been proved by visualizations and image processing, with

an experimental two-DOF manipulator. numerical simulations. Concentration contours of

point and line source diffusion in the boundary

2) A systematic methodology has been layer obtained from visualization data and from a

established for the dynamic analysis of numerical simulation of channel flow are being

geared robotic mechanisms. It is shown that compared in order to verify the accuracy of the

Lagrange's equations of motion can be two techniques. A Lagrangian decomposition of

derived systematically using the minimum the scalar transport correlation into fundamental

number of generalized coordinates, and that physical processes is being carried out using

Engineering Hesearch 23 1991
ensembles of particle paths computed in the popular energy integration procedures, which have

simulation of turbulent channel flow. This provides led to major energy savings in continuous

insight into the physical mechanisms underlying processes over the last decade, must be modified

transport and how they may be modeled. to include this unknown temperature.

Direct numerical simulation programs including Noncontinuous processes which include one or

scalar transport have been developed and tested. more important batch processing steps are also

An algorithm incorporating highly accurate tricubic being studied. An algorithmic approach based on

interpolation for the calculation of particle paths simulated annealing for the scheduling of batch

has been successfully implemented and the processes including due date and inventory

necessary particle path data is now being considerations has been developed and the

computed for evaluation of the Lagrangian scalar interactions of the design with the production

transport decomposition. Experimental data from schedule are under study.

visualization and nine sensor hot-wire

vorticity/velocity measurements in a turbulent

boundary layer at R = 1000 are now available. University Of MassachusettsImages were captured on video tape and 16mm Lowell

movie film for subsequent motion analysis and el

image processing. Department of Electrical Engineering $88,305 Image . proces Lowell, MA 01854 01-C

91-3

University Of Massachusetts Stability and Heat Transfer in Time- University Of Massachusetts Modulated Flows

Chemical Engineering Department $116,000 C Thompson

Goessmann Laboratory 03-A

Amherst,MA 01003-0011 90-3 This project represents an analytical/experimental

effort directed toward understanding the processes A General Procedure for the Synthesis of responsible for the generation of boundary layer

JProcess Flowsheets instabilities in time-modulated flows. In particular

J. Douglas, M. Malone the temporal modulations of the basic state by

harmonic and free-stream vorticity is considered.

This research is focused on developing a more The objectives of this work are to: 1) Develop

general procedure for the systematic synthesis of analytical models describing instability in

flowsheets for chemical processes. These temporally modulated flows. The dynamics of the

procedures intended are to identify the most system is examined using stability analysis and

important process alternatives, the dominant validated against experimental observations. 2)

design variables, and the minimum energy Determine the growth and propagation of unstable

consumption for each alternative in processes disturbances occurring in the viscous region. The

containing vapor, liquid-liquid and/or solid phases. influence of the modulation amplitude and wall

This work will substantially expand process features such as wall curvature are considered. 3)

synthesis capabilities, building on earlier results Examine the stabilizing influence of steady-flow.

which were the basis of a hierarchical synthesis 4) Examine global and local instability resulting

procedure for continuous processes containing from modulation of the free-stream near points of

mixed vapor/liquid phases. mean-flow stagnation. 5) Categorize results

suggestive of possible mechanisms for heat

A hierarchy of decisions and rules for the transfer.

synthesis of liquid-liquid separation systems and

for crystallizer, filter dryer steps have been Models for the transition to chaotic fluid motion in

developed. The generalized flowsheet structure time modulation flow have been developed. It has

has also been identified and an evaluation of the been shown that oscillatory modulation of the

interactions with other separation steps is being basic flow results in successive period-doubling

studied. One important difference between bifurcations of three-dimensional vortical

vapor/liquid processes and solids processes arises disturbances. Above an amplitude threshold these

on account of the optimum operating temperature disturbances exhibit temporally chaotic behavior.

for decanters, dissolvers, and crystallizers. The

Engineering Research 24 1991
Massachusetts Institute Of Massachusetts Institute Of

Technology Technology

The Energy Laboratory $122,300 Energy Laboratory $105,000

Cambridge, MA 02139 03-B Cambridge, MA 02139 03-A

91-3 91-3

Metal Transfer In Gas Metal Arc Welding Synthesis and Optimization of Integrated

T. Eagar, J. Lang Chemical Processes

L Evans

The present research is part of a cooperative

program among faculty at MIT and staff at the The objective of this research is to investigate and

Idaho National Engineering Laboratory (INEL) to develop improved systematic methods for the

develop a sound understanding of the arc welding synthesis and optimization of chemical processes.

process and to develop sensing and control The work to date has focused primarily on

methods that can be used to automate the synthesis of heat and work integration systems for

gas-metal arc process. large-scale continuous chemical plants. In the

past year we have redirected the project to

Previous research on this project mapped the light address methods for synthesis and optimization of

emissions from a welding arc spatially, temporally, batch and semi-continuous processes.

and spectrally. This work identified windows

where it is best to photograph or otherwise view The synthesis of heat and work integration

the weld pool. Later work developed an systems in process plant is important in the design

understanding of the forces controlling metal of new plants and in the retrofitting of existing

transfer in gas-metal arc welding. Welds were plants for energy conversion. A typical process

made with steel, titanium, and aluminum using a plant, such as a petroleum refinery, a

variety of shielding gases and varying the welding petrochemical plant, or a paper mill, requires

current to achieve different metal transfer modes. energy in the form of heat to raise the temperature

This work was done using a laser back-lighting of process streams and in the form of work to

technique developed at MIT which allows one to drive pumps and compressors and meet other

estimate the anode spot attachment on the mechanical energy needs. The goal of heat and

melding electrode. These experiments have led to work integration is to reduce this external energy

a new hypothesis to explain the transition from requirement through better process integration.

globular to spray metal transfer. A mathematical For example, the heating requirement can be

model was based on this model which accounts reduced by allowing hot streams that must be

for the forces due to gravity, surface tension, cooled to exchange heat with cold streams that

electromagnetic, and plasma jet drag. By studying must be heated. Also, the process itself can be

the relative importance of each of these forces, it used to generate mechanical energy by

was shown that 10 to 20 percent higher weld introducing heat engines.

deposition rates could be achieved with pulsed

current welding using different shielding gases. This research has focused on developing

computer-based methods to help engineers

The research during the current year has reviewed synthesize a process with improved energy

methods of filtering the voltage and current integration. The strategy has been to combine

waveforms during pulsed current welding in order modern mathematical programming techniques,

to extract signals which can be used to control the sophisticated rigorous models of the process

process. A new process control system has been utilities system and heat recovery network, and

developed and integrated with the welding heuristic methods to develop an overall

equipment. Work has begun to study methods of methodology that is more powerful than traditional

mechanically controlling droplet detachment from approaches. Methods and computer programming

the welding electrode. techniques of artificial intelligence have been used

where appropriate. An effort was made to

overcome the idealizations characteristic of much

previous process synthesis research to develop

methods that will help engineers solve realistic

industrial problems. The net result of the research

Engineering Research 25 1991
has been an improved understanding of the nature Massachusetts Institute Of

of the problem of energy integration in process Technology

plants. Lab for Manufacturing & Product $158,000

With the completion of three doctoral theses on Cambridge, MA 02139 03-B

the project in the area of heat and work 91-3

integration, the research is now being redirected to Multivarlable Control Of The Gas-Metal Arc

address the synthesis and optimization needs of Welding Process

batch and semi-continuous manufacturing D. Har

processes. These processes are of increasing

importance for the manufacture of high-value T he Gas-Metal Arc Welding Process (GMAW) is

performance products such as those produced by a highly productive means for joining metals and

biotechnology. Yet, the development of systematic is being used increasingly for structures and

computer-based methodologies for batchprocess pressure vessels. It presents a challenging

is only in its infancymtoooisfrh. pmultivariable control problem entailing both

geometric and thermal outputs. These outputs all

combine to determine the strength and toughness

Massachusetts Institute Of of the resulting joint. The overall objective of this

work is to examine the problem of simultaneous

Technology regulation of all real-time attributes of a weld.

Dept of Mechanical Engineering $98,455 Past work has established the viability of

Cambridge, MA 02139 01-C independent control of thermal characteristics and

89-3 the present work is examining the geometric

Dryout In Horizontal and Almost Horizontal aspects of weld pool control.

Heated Tubes

P. Griffith One objective of this work is to develop basic

process modeling and control schemes to allow

Fluidized bed combustors, waste heat, heat independent regulation of the weld bead width and

exchangers and combined cycle gas height. A control model relating wirefeed and

turbine-steam turbine power plants all use travel speed to width and height was developed

horizontal heated tubes with hot gas on one side using transfer function identification techniques

as the heat source. Because the gas side heat applied to a series of step welding tests. The

transfer coefficient is so low, excessive heat resulting discrete transfer function was found to be

transfer and burnout is never a problem. nonlinear in both the static and dynamic parts

owing to a strong dependence upon the input

The most important problem is dryout where ther- magnitudes. This model was then used to

mal fatigue or excessive corrosion due to repeated develop a decoupling controller design that

quenching occurs. Dryout can always be eliminat- cancels the nonlinear behavior using gain

ted by increasing the mass velocity in the tube but scheduling. Proper regulation of the process was

this increases the operating expense so it is demonstrated, but the limited range of control

important to know exactly where the dryout limit is. afforded by this process and the significant

process delays that were in evidence led to very

Previous work has shown that periodic washing poor disturbance rejection. It is apparent that the

and dryout of the tubes in the intermittent (slug GMAW process will need significant modifications

flow) flow regime is the most limiting condition. to overcome these problems.

The primary goal of this project is to determine

whether dryout is due to drainage, evaporation or In an attempt to merge previous results on the

bubble nucleation at the wall. Depending on regulation of thermal characteristics in real-time

which mechanism is dominant, a method for with the geometry control work, we are developing

predicting dryout in non-uniformly heated, high a control system to independently regulate the

pressure, large (2") diameter pipes will be weld bead width and the width of the heat affected

developed and tested. The results will be cast in zone. Initial work is concentrating on simulation of

the form of appropriate boundary conditions for a wide seam welding using an analytical heat

two fluid model of heat transfer in a heated, transfer model as well as a finite difference

horizontal pipe. process model. A key issue in the problem is the

Engineering Research 26 1991
strong coupling between the inputs (current and Massachusetts Institute Of

travel speed) and the outputs. The use of high Technology

frequency transverse motion of the torch is being e no i

investigated as a means of overcoming this Dept of Mechanical Engineering $196,000

coupling. Once the control latitude is increased, a Cambridge, MA 02139 01-A

two variable control scheme based on both video 91-3

and infra-red sensing will be implemented. Modeling and Analysis of Surface Cracks

D. Parks, F. McCllntock

Finally the depth of penetration of a weld is the

most important indicator of weld strength, yet it is This research focuses on the analysis of ductile

the one variable that is essentially impossible to cack initiation, growth and instability in

measure directly. A real-time depth estimator has part-through surface-cracked plates and shells.

been developed based on solution of an inverse The overall approach consists of careful

heat transfer problem. Surface temperature calculations of crack front stress and deformation

measurements are used as inputs to the analytical fields, and correlation of cracking with

model, which then tunes the unknown parameters experimental observations being conducted at the

until predicted temperatures match the measured. Idaho National Engineering Laboratory.

Initial experiments with this model, using surface

temperature measurements from the top and Recently, significant progress has been achieved

bottom of the weld, have shown accurate and in developing and applying a two-parameter

rapid convergence and development of a depth description of crack front fields. The amplitude of

control system based on this estimator is now crack tip deformation is characterized by J or

being processed. CTOD, while the hydrostatic constraint in the

near-tip region correlates well with a parameter

This project is a collaborative program with INEL. related to the so-called T-stress, or second

elastic Williams' eigenfunction.

Massachusetts Institute Of Simplified engineering applications of surface

crack analysis are being developed in the context

Technology of the line-spring model. Specific enhancements

Dept of Mechanical Engineering $81,000 include improved elastic-plastic procedures for the

Cambridge, MA 02139 01-D practically important case of shallow surface

91-2 cracks, as well as simple methods for calculating

Cryotribology: Development of the T-stress along surface cracks fronts.

Cryotribological Theories and Application to

Cryogenic Devices Detailed elastic-plastic stress analyses of cracked

Y. Iwasa structural geometries provide a basis for

interpreting experimental observations, for

The principal objective of this cryotribology (low- quantitatively assessing inherent limitations of

temperature friction and wear) project is to nonlinear fracture mechanics methodology, and for

contribute towards the advancement of cryogenic extending these boundaries through development

systems by examining the basic mechanisms of of two-parameter characterization of crack tip

cryotribology. Because relative motion is essential fields. Simplified but accurate analytical methods

to the operation of many cryogenic devices, an are also under development for analysis of

improved understanding of cryotribology will place surface-cracked plates and shells. Emphasis is

us in a much better position to meet the future placed on better understanding complex

demands that will be required of these low- three-dimensional features of elastic-plastic crack

temperature system. While continuing to generate tip fields.

more cryotribological data, we have also been

expanding our efforts to emphasize the

development of cryotribological theories which will

enable a more systematic approach towards the

design of cryogenic devices, including heliumtemperature (4.2 K) as well as high-Tc

superconducting magnets.

Engineering Research 27 1991
Massachusetts Institute Of Continuing studies have expanded to consider the

~~~Tec~hnr~ology ~combined actions of crushing and solids transport

with particle beds, with particular attention to the

The Energy Laboratory $133,000 size-dependent relative motion of particles to

Cambridge, MA 02139 01-A permit effective removal of fine material as it is

91-3 formed. A novel comminution device has been

Basic Engineering Sciences of Solids conceived to provide the desired crushing and

Comminution separation, and this concept serves to guide

C. Peterson continuing research. Experimental determination

of crushing efficiency within beds has shown a

This work is part of a broader study of the energy maximum efficiency at about 20% bed

and force requirements for fine grinding of compaction, followed by rapidly rapidly declining minerals and coal. Research is directed to the efficiency at greater compaction as remaining void

crushing behavior of individual particles, down to space approaches zero. Contrary to expectations,

perhaps 50 microns, and the behavior of particle thin beds (about 3 particles deep) are not as

beds, including in particular the failure of individual efficient as thick beds (greater than 15 particles

particles within such beds. deep). Preliminary experiments to separate small

and large particles with an upward fluid flow have

Experimental work has been completed on the been very successful.

force and energy necessary to fracture small glass

spheres and on the behavior of beds of glass

spheres, including the fracture of individual Massachusetts Institute Of

spheres within beds subjected to overall a acs Instit

compression. Studies on the fracture behavior of Technology

large (one inch) brittle and plastic spheres have Dept of Mechanical Engineering $111,108

been completed. Cambridge, MA 02139 01-C

89-3

Analytical work has developed a detailed Rheological and Flow Characteristics of

simulation of the overall and interior behavior of Dense Multiphase Slurries Employing a

beds of spheres subjected to compression, Bimodal Model

including the fracture of individual spheres when R. Probstein

sufficiently stressed. The simulation was limited to

a two-dimensional array of three-dimensional The efficient utilization, transport, and handling of

spheres. Correlation of simulated and dense multiphase slurries containing high volume

experimental behavior has been encouraging, but fractions of solid particles, distributed in size from

it became clear that an appropriate failure criterion submicron to several hundred microns, requires

for spherical particles subjected to multiple point the ability to predict the rheological and flow

loads from neighboring particles was necessary. properties as a function of the various physical

Four assumed criteria yielded significantly differing parameters including solids loading, particle shape

bed behavior. and size distribution, stability characteristics, and

solid and fluid properties. Under the grant a

Analytical and experimental work on fracture of rational theoretical and experimental methodology

individual spheres established an appropriate will be developed for the rheological and flow

failure criterion, at least for brittle spheres (which property prediction of dense-phase slurries. The

happens to be the simplest of the four assumed approach models a polydisperse suspension as

criteria). The criterion is also appropriate for inherently bimodal, wherein it is considered to be

plastic spheres subjected to moderate secondary made up of a fine fraction which behaves

loads, but this is not the case when secondary colloidally and imparts to the suspension many of

loads are comparable to the major point load. its important rheological and flow characteristics,

and a coarse fraction which behaves as if it were

With the confirmation of an appropriate particle in a pure liquid with the same viscous behavior as

fracture criterion, at least for most particles, the the colloidal suspension and raises the apparent

bed simulation is now deemed suitable for use as viscosity through hydrodynamic interactions.

a design tool.

Engineering Research 28 1991
The bimodal model has been shown to be very model both a ball falling through a quiescent

successful in application to a truly bimodal suspension and the hydrodynamic interaction of

suspension, where the shear dependent viscosity many particles in shear flow. The threebehavior of the colloidal fraction is determined dimensional dynamics of the interactions of up to

experimentally. For polymodal multiphase flows 40 particles have been calculated, and excellent

the bimodal model is being extended, through agreement achieved with experimental data.

analysis and experiment, to find a rational method

to divide a continuous size distribution into a

colloidal and a coarse fraction, and to define the University Of Minnesota

effect of a non-uniform size distribution of each Dept o Mechanical Engineering $ 0

fraction. Additional rheological information on the Minneapolis, MN 55455 01-B

colloidal fraction, including the effects of the 87-4

electrochemistry, and the particle shape and size The Impact of Separated Flow on Heat and

distribution is also being obtained. Mass Transfer

R. Goldstein

Massachusetts Inst Of Tech1 Separation occurs in many processes involving

Dept of Chemical Engineering $55,000 fluid flow. In the separated flow region reverse

Cambridge, MA 02139 06-C and secondary currents (also vortices in some

91-3 situations) form which give rise to considerable

Los Alamos National Lab2 variations in heat or mass transfer. Often a small

Design Engineering Division $103,000 area is covered by the separated flow, rendering

Los Alamos, NM 87545 06-C a very sharp gradient in the local temperature or

91-3 concentration. Detection of the occurrence of

Sandia National Laboratories 3 sharp gradients, their extent and the factors influencing them, are the subjects of this study. A

Fluid & Thermal Sciences Dept $103,000 mass transfer measurement system capable of

Albuquerque, NM 87185 06-C sensing minute changes in mass transfer rate over

Hr91-3 a very small region (measuring data points 0.03

Macrostatistical Hydrodynamics mm apart) has been developed and is being used.

H. Brenner1, A. Graharn, L Mondy3 The studies consider flow around the base of

circular and square cylinders projecting out of a

This research aims to correlate the macroscopic plate, flow over roughened surfaces, flow through

rheological behavior of suspensions with their perforated plates, and flow in the corner and

statistical microstructure. statistical microstructure. This This fundamental fundamental downstream of a bend in a square cross-section

knowledge will benefit a host of technologies, duct. Computational modeling of some of these

including geothermal energy production, petroleum flow cases compares well with the experimental

production and refining, and synfuels processing. results

Our approach involves a novel combination of

experiments, numerics, and theory. Falling balls

settling through transparent suspensions of i i f Minn ta

neutrally buoyant particles are tracked optically; U ersy Mnne

radiography is used for opaque suspensions. Dept of Aero Eng & Mechanics $164,268

High-speed video and image processing serve to Minneapolis, MN 55455 01-C

observe and record the instantaneous falling ball 90-3

motion. Nonlinear regression is applied to Stability Studies of Core-Annular Flows

transform between camera and real-space D. Joseph

coordinates. Data are interpreted in terms of the

average and higher moments of the position and The objectives are to understand and control drag

velocity distributions of the falling ball. reduction in water lubricated pipelines and to

Experimental measurements covering a large determine conditions of stability in water film

range of conditions show the deviations from the cooling of water vapor (with phase change) for

average settling motion of the ball to be much possible application to nuclear safety. We have

larger in the vertical direction than horizontally. developed a successful linear theory for predicting

Numerical calculations have been performed to regimes of lubricated flow of oil and water and we

Engineering Research 29 1991
have new experimental results in lubricated flow in films. Substrate surface preparation has only

vertical pipes. We are now doing nonlinear theory affected initial nucleation on super-polished single

and preparing experiments on water lubricated crystal silicon. Specific film growth mechanisms

pipelining of coal-oil dispersions. We are have been identified for different deposition

generally supported and encouraged by Shell conditions. Several of these results have not been

Development in Houston. We are world leaders in reported previously.

this subject. We are going to apply the methods

we use for water lubricated pipelining to nuclear An initial model has been formulated describing

safety, but we don't know how it will turn out. the temperature, velocity and concentration

distributions in a plasma reactor approximating the

triple torch reactor. This model indicates

University Of Minnesota extremely high temperature and concentration

Dept of Mechanical Engineering $134,998 gradients in front of the substrate giving rise to

Minneapolis, MN 55455 06-C strong thermo-diffusion effects as the controlling

88-4 mass transport in the boundary layer. Diagnostics

Thermal Plasma Processing of Materials will be used to verify the model results.

E. Pfender

The objective of this research project is to study National Institute Of Standards

analytically and experimentally specific thermal & Technology

plasma processes for materials treatment. Chemical Eng Science Division $104,000

Processes of interest include the synthesis of Center for Chemical Technology 01-C

ultrafine ceramic powders and of films. Boulder, C 80303-3328 89-3

During the past year our effort has concentrated Convection and Dispersion in Coarseon characterizing the thermal plasma chemical Packed Beds

vapor deposition (TPCVD) process of diamond M. Jones, J. Wolfe

films onto various substrates. TPCVD has the

advantages that the species thought to be the One of the most widely used items of industrial

primary reagents in the deposition of diamond equipment is the packed bed in which, commonly,

films, namely CH3 and atomic hydrogen, are a vertical throughflow exists through a packing

generated in abundance leading to significantly which is relatively coarse. The presence of

increased deposition rates. The task is to control temperature or compositional gradients in

the recombination processes in the nonequilibrium conjunction with the stochasticity of the packing on

boundary layer between the plasma and the the scale of observation leads to flow structures

cooled substrate. In our study we have used the which may be hard to predict but which are, in any

triple torch reactor developed previously under this case, not uniform. The flow structures observed

program to obtain good mixing of the reactants under these conditions are being studied with the

CH4 and hydrogen with the argon - hydrogen aid of an array of fiberoptic probes which detect

plasma jets. the concentration of a fluorescent dye injected with

the throughflow. This technique allows timeIn a systematic study the influences of the resolved imaging of the flow structure in the plane

pressure in the deposition chamber, of the plasma of the array. Considerable insight into the state of

composition, and of the substrate temperature, convection may be obtained from some of the

material and surface pretreatment have been statistics available from individual probe

determined. Polycrystalline films have been responses. These include the residence time

deposited on a variety of substrates at surface distribution, the spatial distribution of transit times,

temperatures between 800 and 1200°C with and their means and standard deviations.

deposition rates around 60 m/hr. Homoepitaxial

films have been grown on 1 mm diameter diamond Experiments have been performed with downward

seed crystals with growth rates up to 200 m/hr at flow of water in a packing of uniform diameter,

temperatures of 1400°C. The optimum pressure poured, glass spheres with a vertical temperature

has been found to be around 270 Torr, CH4 to gradient. The transition of the flow structure has

hydrogen ratios of 1 to 6% have yielded good been observed for a range of temperature

Engineering Research 30 1991
gradients characterized by a Rayleigh number, extend significantly the existing state of the art for

and different flow rates characterized by a thermal properties measurements and make it possible to

Peclet number. The transition to mixed forced- study a wide range of complex fluid systems (e.g.,

free convection is not abrupt as would be highly polar, electrically conducting, and reactive

predicted from the volume-averaged equations of fluids) under conditions which have been

motion and energy. Instead, the flow structure previously inaccessible. This project also includes

undergoes distributions which indicate a random benchmark experimental measurements on

structure which gradually changes to approximate systems containing alternative refrigerants, on

modes determined from the confining geometry. aqueous solutions, and on carefully selected

Dispersion obtained from the standard deviation of systems with species of diverse size and polarity

dye transit times at the plane of observation shows that are important to the development of predictive

a generally increasing trend, with a small models for energy-related fluids.

maximum preceding the occurrence of circulating

(free convection) flows. The interpretation of these

observations is aided by numerical solution of the National Institute Of Standards

governing equations for grids with randomly & Technology

distributed porosity. These show similar

precursors to circulating flow associated with Superconductor & Magnetic

neutrally buoyant stagnant regions of the bed. Measurements Group $98,488

Electromagnetic Technology Div 06-C

Boulder, CO 80303 89-3

National Institute Of Standards Low Resistivity Ohmic Contacts Between

& Technology Semiconductors and High-T,

Thermophysics Division $530,000 Superconductors

Gaithersburg, MD 20899 03-B J. Moreland, J. Ekin

Boulder, CO 80303 91-5

The purpose of this project is to fabricate and

Development of Measurement Capabilities for characterize contacts between high-T

the Thermophyslcal Properties of Energy- superconductors (HTS) and semiconductors.

Related Fluids Developing a method for optimizing the current

R. Kayser, J. Levelt Sengers, M. Moldover, W. capacity of such contacts will extend the

Haynes application of HTS materials to semiconductor

hybrid technologies that have HTS interconnects

The major objectives of this project are to develop (both on-chip and package) and proximity HTS/

state-of-the-art experimental apparatus that can semiconductor/HTS SNS Josephson Junctions.

be used to measure the thermophysical properties Presently, these are some of the most promising

of a wide range of fluids and fluid mixtures HTS applications, but an essential first step is the

important to the energy, chemical, and energy- development of stable ohmic contacts between

related industries and to carry out carefully semiconductors and HTS materials.

selected benchmark measurements on key

systems. The research is being done jointly by The project is now focused on YB2Cu 3O, (YBCO)

two groups within the Thermophysics Division of thin-films grown on Si wafers. Recent discoveries

the NIST Chemical Science and Technology have shown that is possible to grow high quality

Laboratory; one group is located in the HTS films on Si using laser ablation deposition

Gaithersburg, MD laboratories and the other at the and a yttria stabilized zirconia buffer layer between

Boulder laboratories. The specific measurement the YBCO film and the Si. Processing steps are

capabilities to be developed in this project include being optimized for depositing and patterning

new apparatus for transport properties (thermal YBCO films on Si to form contact vias to the Si

conductivity and viscosity), for thermodynamic substrate. The goal is to minimize the specific

properties (pressure-volume-temperature data resistance of the contacts using techniques that

and enthalpy), for phase equilibria properties are compatible with standard Si processing.

(vapor-liquid equilibria, coexisting densities, and

dilute solutions), and for dielectric properties

(dielectric constant). These new apparatus will

Engineering Research 31 1991
The City University Of New York In general the number of variables to be controlled

The City College $ 0 must be equal to the number of variables available

The Benjamin Levich Institute 01-C for manipulation. However experience shows that

for Physico-Chemlcal Hydrodynamics 90-3 often satisfactory results can be obtained by

New York, NY 10031 controlling a smaller number of variables. That is

referred to as practical controllability. The object

The Rheology of Concentrated Suspensions of the proposed research is to provide a rational

A. Acrivos basis for making optimal choices of the necessary variables.

This research program aims to investigate the flow

of concentrated suspensions of non-colloidal To focus the research, it is proposed to address

particles from the fundamental point of view. this basic problem in the context of a Fluidized

Earlier studies by the principal investigator and his Bed Catalytic Cracker (FCC). In particular the

associates have shown that the rheology of such question of the dependence of controllability on

systems is strongly affected by the shear-induced the system design will be addressed. The choice

migration of particles from regions of high shear to of this example is governed by the availability of a

low and from high concentrations to low which, by reasonable nonlinear model of FCC. The specific

distorting the particle concentration profile, can steps to be taken will include a determination of

lead to an erroneous interpretation of the operating set points for different measured

experimental measurements. This shear-induced variables and different control variables, the

particle diffusion is also responsible for the dependence of process stability on the choice of

phenomenon of viscous resuspension whereby, in those variables, and implementation of a particular

the presence of a shear flow, a settled bed of type of partial control, viz., cascaded control.

heavy particles can resuspend even under

conditions of vanishingly small Reynolds numbers. In addition to the FCC, it is proposed to carry out

a similar investigation of partial control of

Viscous resuspension is being studied both polymerization reactors.

theoretically and experimentally in various

unidirectional flows, e.g. a 2-D Hagen-Poiseuille

flow, as well as a Taylor-Couette system. Excel- The City University Of New York

lent agreement has been found to-date between The City College $98,500

the experimental results and the theoretical The Benjamin Levich Institute 06-C

predictions even though the latter do not entail the of Physico-Chemical Hydrodynamics 91-3

use of adjustable parameters. New York, NY 10031

Studies in Premixed Combustion

The City University Of New York G. Slvashinsky

The City College $120,000

The Benjamin Levich Institute 03-A The objective of this research is a combined

of Physico-Chemical Hydrodynamics 91-3 analytical and numerical study of the influence of

New York, NY 10031 various hydrodynamic, thermal-diffusive and

reaction rate factors on speed, shape, stability and

Partial Control of Complex Processing the extinction limits of premixed gas flames.

Systems Different modelling techniques will be employed to

R. Shinnar, L Rinard reduce the study of pertinent combustion systems

to simple approximate problems tractable either

In many instances the control of a process can be analytically or numerically. Specifically, the project

managed by accessing and manipulating only a is concerned with (1) the dynamics of premixed

limited number of variables in the presence of flames spreading through a one- and multiplemany. The inevitable problem is how to exercise scale system of eddies and with the further

the necessary choices. While empirical, practical development and refinement of the associated

rules for making those choices exist, there is as cascade-renormalization concept of turbulent

yet no sound theoretical basis for solving problems flame speed; (2) the intrinsic dynamics and the

in partial control of complex processes. pattern formation in premixed flames sustained by

Engineering Hesearch 32 199
the thermal-diffusive and thermal expansion rigorous relation which links the fluid permeability

induced mechanisms of flame instability; (3) the to the electrical conductivity of porous media has

hydrodynamical aspects of combustion limits with been derived. Work has begun on the study of

particular attention to the phenomena of flame the dispersion of a passive tracer due to random

extinction by one- and multiple-scale periodic velocity fields.

flowfields and extinction in upward and downward

propagating flames in tubes; and (4) the

development of new numerical methods especially Northwestern University

assigned for the free-boundary problems of Dept of Civil Engineering $84,158

flame-flow interaction and spontaneous pattern Evanston, IL 60208 03-B

formation in premixed flames. 89-3

Quantitative Non-Destructive Evaluation of

High Temperature Superconducting Materials North Carolina State University J. Achenbach

Dept of Mech & Aero Eng $95,533

Raleigh, NC 27695-7910 06-A A crack in a solid body can, in principle, be

89-4 detected and characterized by its effect on an

Transport Properties Of Disordered Porous incident pulse of ultrasonic wave motion.

Media From The Microstructure

S. Torquato The work on this project is concerned with

applications of the scattered field approach to the

This research program is concerned with the detection and characterization of cracklike flaws.

quantitative relationship between transport The work is both analytical and numerical in

properties of a disordered heterogeneous medium nature. Several forward solutions to model

that arise in various energy-related problems (e.g., problems have proven to be very helpful in the

thermal or electrical conductivity, trapping rate, design of experimental configurations. They are

and the fluid permeability) and its microstructure. also valuable in interpreting scattering data for the

In particular, we shall focus our attention on inverse problem.

studying the effect of: porosity, spatial distribution

of the phase elements, interfacial surface The efficacy of ultrasonic methods to detect and

statistics, anisotropy, and size distribution of the characterize a crack depends on topographical

phase elements, on the effective properties of features of the crack faces, the presence of

models of both unconsolidated media (e.g., soils inhomogeneities in the crack's environment, and

and packed beds of discrete particles) and on the mechanical properties in the near-crack

consolidated media (e.g., sandstones and sintered region. In this work the effects on the scattered

materials). ultrasonic field of various features of fatigue and

stress corrosion cracks, such as partial crack

Both theoretical and computer-simulation closure, the presence of microcracks and

techniques have been employed to quantitatively microvoids, and near-tip zones of different

characterize the microstructure and compute the mechanical properties have been investigated.

transport properties of disordered media. Most of the results have been obtained by

Statistical-mechanical theory has been used to formulating a set of singular integral equations for

obtain n-point distribution functions and to study the fields on the boundaries of the scattering

percolation phenomena in continuum obstacles. These equations have been solved

random-media models. This has led to accurate numerically by the boundary element method, and

predictions of transport properties of realistic the scattered fields have subsequently been

models of isotropic as well as anisotropic obtained by using representation integrals.

heterogeneous media. An efficient Brownian

motion computer-simulation methodology has For the configurations examined in this work, crack

been developed to exactly yield effective diffusion closure has the most significant effect on far-field

properties such as the conductivity, dielectric scattering.

constant, magnetic permeability, diffusion

coefficient, and the trapping rate associated with

diffusion and reaction among sinks. The first

Engineering Research 33 1991
Northwestern University Northwestern University

Dept of Chemical Engineering $121,300 Dept of Eng Sci & App Math $51,000

Evanston, IL 60208 01-B Evanston, IL 60208 01-C

89-3 91-3

Thinning and Rupture of Thin Uquld Films Effects of Capillarity of Macroscopic Flow In

S. Bankoff, S. Davis Porous Media

M. Miksis

The objective of this work continues to be the

study of the dynamics, stability, and rupture The objective of this project is to study the effects

(including contact-line motions) of thin liquid films, of capillarity on the motion of a fluid in a porous

especially with heat and/or mass transfer. The material. The primary concern will be the

two- and three-dimensional structure of surface micromechanics of the fluid motion when

waves on a heated inclined plane, has been interfaces are present and its effect on the

examined and the experimental technique has macroscopic flow. These interfaces could exist as

been developed to measure accurately the a liquid moves into an unsaturated porous material

surface-wave shapes, frequencies and amplitudes or when there are two phases within the porous

on thin liquid films draining down an inclined plate material, e.g., liquid/gas or liquid/liquid. Attention

under adiabatic or heating conditions, for will be directed to understanding and modeling the

comparison with theoretical predictions. dynamics of these interfaces and then relating

their dynamics to the macroscopic behavior of the

The evolution equation for two-dimensional material.

disturbances incorporates viscosity, gravity,

surface tension, thermocapillarity, and evaporation One of the central concerns of this work will be to

effects. The linear theory derived from this understand how the motion of the contact line, i.e.,

describes the competition among the instabilities. the line of intersection of a liquid/liquid or

Numerical solutions of the evolution equation liquid/gas interface and a solid, influences the

describe the finite-amplitude behavior that motion of the fluids. Recent work has been

determines the propensity for dryout of the film. directed to solving for the evolution of a contact

Among the phenomena that appear are the line using analytical and numerical methods. Also

tendency to wave breaking, the creation of recently the dissipation associated with the motion

secondary structures, and the pre-emption of of a contact line and how this dissipation manifests

dryout by the mean flow. A three-dimensional itself in a macroscopic model of wave propagation

evolution equation was also derived that contains in a partially saturated porous material has been

surface-wave instability and nonlinear saturation. investigated. The microscopic flow problems in a

A new secondary three-dimensional instability was porous material can now be studied using these

identified. Unlike other secondary instabilities results. Also attention will be directed to problems

found in many shear flows, the instability does not concerned with the fundamental modeling of the

require a threshold amplitude, so that all two- motion of a contact line. This is an important

dimensional permanent waves on vertical plates aspect of the work since the dynamics and

become unstable to three-dimensional dissipation associated with the motion is very

disturbances. The nonlinear evolution of three- dependent upon the model used for the contact

dimensional layers, including the finite-time line motion.

behavior of the secondary instability, is studied by

posing various initial-value problems and

numerically integrating the long-wave evolution

equation.

Engineering Hesearch 34 1991
Northwestern University inlet and exit. It is important to determine to what

School of Eng & Applied Science $210,155 extent the ubiquitous time-varying fluctuations at

Evanston, IL 60208-3120 06-C the inlet, which may be of small or large

91-3 amplitude, can be expected to affect the qualitative

Mixing of Immiscible Fluids In Chaotic Flows or quantitative behavior of the downstream flow.

and Related Issues For example, it appears that close to neutral

J. Ofttno stability in a stratified flow, conditions exist where

the irregularity in the interfacial waves can be

In spite of its universality and practical traced to inlet noise. However for other nearby

implications, the understanding of the conditions the waves show no evidence of the

fundamentals of mixing remains rather incomplete. effects of inlet noise.

This work focuses on basic experimental and

computational studies along two main themes with The present approach is to characterize these

the objective of establishing a framework capable flows by using experimental measurements of

of addressing mixing problems encountered in wavelength and amplitude for periodic waves, and

nature and technology: (1) investigations of amplitude and time-spacing between irregular

chaotic mixing of single fluids in deterministic two- disturbances. These measurements are

and three-dimensional flows, and (2) dynamics of interpreted using linear and nonlinear analysis,

microstructures in such flows (e.g., stretching, based on spatially-varying disturbances, of the

breakup, coagulation, etc.). Work in area (1) is Navier-Stokes equations. Additional insight

underway and a clear picture is emerging. comes from some of the recent developments in

Experimental work is planned to address the understanding the generic behavior of nonlinear

problems listed under area (2). However, most of dynamical systems (e.g. intermittency and chaos)

the results to-date are due to simulation which but with careful recognition of the differences

focused on coagulation of point particles in chaotic between open systems and the typically-studied

flows. The particles are convected without closed systems (e.g. Taylor-Couette flow).

diffusion and allowed to coagulate with probability

one when their mutual distance is less than their

diameters. The most significant finding is that Oak Ridge National Laboratory

under "well mixed" conditions the system behaves Engineering Physics $972,000

as if the particles were moved by Brownian motion and Mathematics Division 03-C

and a simple kinetic model describes the main Oak Ridge, TN 37831 87-5

results. The poorly mixed case is considerably

more complex. In this case spatial Center for Engineering Systems Advanced

inhomogeneities result from competition between Research (CESAR)

the rate of coagulation and mixing, and trapping R. Mann, F. Pin

and leaking of clusters due to KAM surfaces.

The Center for Engineering Systems Advanced

Research [CESAR] is established at Oak Ridge

University Of Notre Dame National Laboratory to address long-range,

Department of Chemical Engineering $52,000 energy-related research in intelligent machine

Notre Dame, IN 46556 01-C systems. These systems are intended to plan and

91-3 perform a variety of tasks in incompletely known

Study of Interfacial Behavior in Cocurrent environments, given only qualitatively specified

Gas-Liquid Flows goals. The Center provides a focal point for

M. McCready interdisciplinary research in machine intelligence,

cognitive systems, advanced control, and systems

The objectives of this work are to develop an engineering. Research objectives are chosen to

understanding of various types of small-scale (e.g. address the technology-base requirements for

waves) and large scale (e.g. slugs) disturbances DOE missions that rely on the use of robotics and

which are observed in cocurrent gas-liquid flows. intelligent machines. In particular, research

concentrates on issues related to autonomous

Typical gas-liquid systems are "open" flows where systems, unstructured dynamic work

there is no feedback of information between the environments, and multiple cooperating robotic

Engineering Hesearch 35 199
systems. Results from CESAR research in concentrate the dilute aqueous components of

automation-related technologies and intelligent bioconversion systems or waste streams from

machines can increase productivity and safety in energy processes. The research emphasis will be

the development and operations of DOE- on separation concepts that utilize solid-fluid

sponsored systems. Potential and actual interactions with an initial study of the use of

applications include emergency situations, remote biological materials (certain microorganisms and

operations, resource exploration, transportation plant and animal tissue) as bioadsorbents for the

systems, advanced power generation systems, isolation and concentration of dissolved metals.

and environmental restoration and waste

management. Advanced bioreactor/biosorber concepts - Fixedand fluidized-bed bioreactors and/or biosorbers

CESAR is intended to be a national resource, and using immobilized bioreagents are advanced

a major objective is to disseminate R&D concepts that have the potential for significantly

accomplishments freely and comprehensively. increasing productivity. However, such systems

Results and technology advancements are are not well defined, since they may contain three

distributed through publications in the scientific or four interacting phases, including a changing

literature, through organization of workshops on gas phase. The coupling of hydrodynamics, gas

selected topics, and through the development of generation or depletion, gradients of phase

prototype systems that demonstrate concepts and fractions, and biokinetics in continuous columnar

new methodologies. CESAR cooperates with systems will be investigated and predictive

universities, laboratories and industry, serving as mathematical models will be developed.

a collaborative research facility to provide guests

with access to state-of-the-art and often unique

equipment in a stimulating research environment. Ohio State University

Physics Department $66,000

Columbus, OH 43210 06-C

Oak Ridge National Laboratory 91-3

Chemical Technology Division $103,000 Turbulence and Spatio-Temporal Chaos

Oak Ridge, TN 37831 06-A C. Jayaprakash, F. Hayot

89-3

Bloprocess Engineering Research for Energy This program deals with the dynamics of nonApplications linear systems. It concerns three significant areas

C. Scott of research:

This program will support engineering research in (1) the study of spatial coherence and temporal

three primary areas that are critical to an chaos in systems with many degrees of

expanding use of advanced bioprocessing systems freedom: as model systems, coupled maps

for energy production and conservation: (1) on d-dimensional lattices will be investigated.

efficient biocatalytic systems, (2) innovative

bioseparations approaches, (3) advanced (2) the application of renormalization group

bioreactor concepts. techniques to non-equilibrium systems, and

the problem of understanding non-linear

Efficient biocatalytic systems - Several advanced partial differential equations by deriving

bioreactor concepts require that the biological effective stochastic ones at long wavelengths.

catalyst (microorganisms or active fractions) be

retained in the bioreactor at high concentrations in (3) a systematic study of amplitude equations for

a microenvironment that enhances biological various physical situations, with emphasis on

activity. A fundamental understanding of the basic the effects on patterns of non-variational

kinetics and dynamics of such biocatalyst systems terms in the equations.

and a predictive mathematical model will be

developed.

Innovative bioseparations approaches -Advanced

separations concepts will be needed to isolate or

Engineering Research 36 1991
Oregon State University objective of this study is to develop an

Dept of Mechanical Engineering $102,987 understanding of the impact of array geometry,

Corvallis, OR 97331-6001 01-B surface properties, and incident radiation

91-3 characteristics on radiation heat transfer in the

Radiative Transfer Through an Array of array. The results of the study will be used to

Discrete Surfaces establish criteria for the valid application of

J. Welty participating media models to arrays of fixed

discrete surfaces.

Radiation heat transfer in arrays of discrete

surfaces is an important class of radiative transfer The approach consists of using an innovative

problems. Analytical solutions are difficult for even Monte Carlo model optimized for evaluating arrays of fixed discrete surfaces to evaluate radiation the simplest array and, as an array increases in

complexity, the computational time for a traditional heat transfer in arrays with a range of geometric

Monte-Carlo model becomes excessive, even for characteristics. The Monte Carlo model will be

supercomputers. validated by comparison with experimental results

being developed by Oregon State University in a

This experimental study is designed to explore parallel study. Following validation, the Monte

basic relationships between array geometry Carlo model will be used to conduct parametric

(spacing, packing arrangement, and element evaluations of a range of array geometries. The

shape), surface properties, and radiative transfer results of the parametric studies will be used as a

through an array. The information resulting from benchmark for comparison with analytical

this study may also be useful in establishing approaches that model the array as a participating

criteria for the valid application of participating medium.

media models to arrays of fixed discrete surfaces.

FY 1991 accomplishments consist of initiating

The experimental apparatus is in the development Monte Carlo code modification to allow

and initial testing stage. It consists of a uniform, comparisons with experimental results and

high intensity, collimated, chopped, visible light simulations used to assist the design of the

source; a two-dimensional axi-symmetric array; a experimental apparatus.

highly directional fiber-optic probe connected to a

PMT; and a lock-in amplifier. Initial experiments

will involve two element shapes, one with a circu- University Of Pennsylvania

lar cross-section and one with a high-aspect-ratio Electrical Engineering Department $108,502

rectangular cross-section; and two types of sur- Philadelphia, PA 19141 06-C

faces, highly reflective specular and highly reflec- 91-1

tive diffuse. An important use of the initial results Radiative Interactions with Micromachined

is verification of a numerical code that will be used Surfaces: Spectral Angular Polarized

to direct subsequent experimental investigations. Emittance

J. Zemel

This work is being carried out in cooperation with

Battelle, Pacific Northwest Laboratory. Recent theoretical and experimental studies have

shown that the basic approach leading to the

conventional views about the nature of black body

Pacific Northwest Laboratory radiation fails when the size of the cavity is

Battelle Memorial Institute $75,000 comparable with the wavelength of the incident

Richland, WA 99352 01-B radiation. Such a situation can arise when light

91-3 interacts with periodic microgrooves inscribed on

Radiative Transfer Through Arrays of a surface. The detailed nature of such an

Discrete Surfaces with Fixed Orientation interaction may be studied by means of spectral,

M. Drost angular, polarized emittance (SAPE).

Radiation heat transfer in an array of discrete Preliminary results show that SAPE allows the

surfaces is an important and poorly understood measurement of the effects of thermally excited

class of radiative heat transfer problems. The standing waves in the microgrooves on the

Engineering Hesearch 37 1991
scattering of the incident radiation. It was found efficient (close to 100%) beam

that indeed there are standing waves in the interior shaping/concentration/ collimation of weakly

of the microgrooves, or slots. Those waves spatially coherent and quasi-uniform

couple efficiently to the incident radiation as well large-aperture optical fields (so called

as to the surface plasmons. The measured quasi-homogeneous fields, which are more

dependence of the latter coupling on the depth of general than Lambertian ones), using an optimized

the slot cannot be accounted for fully by the higher-hierarchy architecture of longitudinal and

existing theory. Measurements of the radiation transversal, imaging and nonimaging optical

scattered by the microgrooves shows that elements (nonimaging cones, lenses, diffusers,

spontaneous emission is inhibited in some holographic optical elements (HOEs)). The

directions. It is possible that this unusual behavior proposed theoretical model holds for the

may find eventually practical applications in quasi-homogeneous radiation emitted by the

electro-optic devices. state-of-the-art of the majority of high energy and

coherent and noncoherent electromagnetic

This research program call for determining how sources.

the geometry of the microgrooves affects the

interaction between the incident radiation and the

standing waves inside the slots; determining the Physical Sciences Inc.

role played by the material properties of the 20 New England Business Center $123,110

micromachined surfaces on the polarized, angular Andover, MA 01810 06-A

emission; and determining the necessary 88-4

corrections to the Stefan-Boltzman radiation law Experimental and Theoretical Studies of

necessitated by the small size of the scattering Condensation In Multicomponent Systems

cavities. M. Frish, G. Wllemski

This research program comprises experimental

Physical Optics Corporation and theoretical studies of nucleation and

2545 W. 237th Street, Suite B $154,621 condensation in multicomponent gas mixtures.

Torrance, CA 90505 06-B The program goals are: (1) to improve basic

89-3 understanding of nucleation and droplet growth,

Nonuniform Llouville Transformers for (2) to stringently test theories of nucleation at high

Quasi-Homogeneous Optical Fields nucleation rates and under nonisothermal

J. Jannson conditions, (3) to develop improved theories where

needed, (4) to enlarge the data base for systems

In this program, Nonuniform Liouville Transformers of both fundamental and practical interest, and

(NLT) are proposed for an important class of (5) to provide reliable means for predicting the

quasi-homogeneous optical fields containing those behavior of mixtures used in practical applications

emitted by thermal (Lambertian) and other such as turbo-machinery. Experimentally,

convectional sources, as well as by the majority of condensible vapors mixed with a carrier gas are

multi-mode high-energy (CO2, Nd:YAG, Excimer, cooled in a supersonic nozzle to obtain high

X-ray, etc.) lasers and semiconductor lasers nucleation rates. The nozzle is designed to

(including laser diodes (LD), which are important ensure that steady-state nucleation occurs and to

sources in local area networks (LANs)). These give satisfactory spatial resolution of the

NLTs are nonuniform, nonimaging beam-shaping temperature profile. Laser light scattering and

systems acting on the basis of the general energy interferometry are used to detect the "onset" of

transport equations for the phase-space density condensation and to monitor subsequent droplet

(related to the generalized Louville theorem) and growth.

the power flux vector. The proposed theoretical

model is more general than those based on Experiments on condensing water vapor have

geometrical optics (including Winston's nonimaging shown that the number density of water droplets

optics), yet less general than that based on either falls sharply after an initial rapid increase. This

the scalar diffraction or electromagnetic theory. previously unobserved behavior appears to be due

The fundamental goal of this program is to find a to polydispersity of the droplet size distribution

theoretical and engineering solution for highly which favors growth of larger droplets at the

Engineering Research 38 1991
expense of smaller ones. Theoretical calculations achieved without heat loss to the rod, and that

of the droplet size distribution along the flow axis flame curvature has a significant effect on the

support this interpretation. The calculated size flame response.

distribution broadens rapidly; large numbers of

large droplets (9 nm radius) are already present at

the observable onset of condensation. The rapid Purdue University

growth in number and size of these large droplets School of Mechanical Engineering $88,901

is responsible for the latent heat release that West Lafayette, IN 47907 01-C

disturbs the gas flow. These results contradict the 90-3

conventional view of condensation in nozzles. In Effect of Forced and Natural Convection on

that view, onset is attributed to the rapid Solidification of Binary Mixtures

nucleation of a monodisperse cloud of very tiny F. Incropera

microclusters (0.4 nm radius) which then grow in

a number-conserving fashion. This work shows This study deals with the influence of combined

that nucleation and condensational growth do not convection mechanisms on the solidification of

occur in separate stages beginning at onset, and binary systems. A major accomplishment of

it establishes both the presence and importance of research performed to date has been the

large droplets at the onset of condensation. development and numerical solution of a

continuum model, which uses a single set of

equations to predict transport phenomena in the

Princeton University liquid, "mushy" (two-phase), and solid regions of

Dept of Mech & Aero Eng $91,859 the mixture. Calculations have been performed for

Princeton, NJ 08544 06-B two-dimensional, aqueous salt solutions involving

90-3 forced convection, thermo/solutal natural

Mechanisms and Enhancements of Flame convection, and/or thermo/diffusocapillary

Stabilization convection. The calculations have revealed a

C. Law wide variety of rich and robust flow conditions,

including important physical features of the

This program aims to gain fundamental solidification process which have been observed

understanding of the structure and stabilization of experimentally but have heretofore eluded

premixed and diffusion flames through theoretical prediction. These features include doubleand experimental investigations. Two projects diffusive layering in the melt, development of an

were completed during the reporting period. irregular liquidus front, remelting of solid,

development of flow channels in the mushy region,

In the first project, it is demonstrated that and the establishment of characteristic

conventional activation energy asymptotic analysis macrosegregation patterns (regions of significantly

of premixed flames lacks an additional relation for different composition) in the final solid.

complete closure except for some special cases,

that this deficiency is caused by the approximation The primary objective of current studies is to

of the reaction term as a delta function in the determine the manner in which externally imposed

reaction-sheet limit, and that imposition of forces influence thermo/solutal convection in the

arbitrary closure relations could lead to 0(1) errors mushy and liquid regions during solidification of a

in the solution. It is subsequently shown that binary mixture. A special goal is to determine

closure, to the needed 0(E) accuracy in the means by which the forces may be used to offset

solution, can be achieved by locating the reaction or dampen thermo/solutal convection, thereby

at the "center of reaction", which is based on the reducing macrosegregation and attendant casting

first moment of the reaction rate function about the defects. Separate consideration is being given to

location of its maximum point, the effects of magnetic and centrifugal forces on

solidification in binary metallic alloys and aqueous

In the second project the structure and salt solutions, respectively. Predictions based on

stabilization mechanism of an inverted flame the continuum model are being compared with

situated over a thin rod in a uniform flow has been measurements obtained for metallic (Pb-Sn) and

studied both experimentally and theoretically. The aqueous (NH4 CI-H 20) systems.

results seem to indicate that stabilization can be

Engineering Research 39 1991
Purdue University devices, at very high heat fluxes. The mode of

School of Nuclear Engineering $104,000 heat transfer is subcooled nucleate boiling, and

West Lafayette, IN 47907 01-C the limiting phenomenon is the critical heat flux

90-3 (CHF). Very large heat fluxes can be

Interfacial Area and Interfacial Transfer in accommodated on a steady basis with pure water

Two-Phase Flow by use of large subcoolings, high velocities, small

M. Ishii tube diameters, and short tubes. It is expected that simultaneous use of several enhancement

The objective of the research program is to techniques will extend the maximum heat flux to at

develop instrumentation methods, experimental least 5x10 W/m2, which would be higher than

data base and analysis leading to predictive reported in any study to date. The wall

models for describing the interfacial structure and temperature characteristics, usually presented as

behaviors of two-phase flows. In terms of the flow a boiling curve, are unknown at such high heat

structure, the local void fraction, interfacial area fluxes.

concentration, fluid particle size distribution and

flow patterns in vertical two-phase flow systems An experimental program has been designed to

are studied in detail. For the purpose of systematically investigate the effects of subcooling

understanding the dynamic behaviors, the velocity, tube geometry, and enhancement

interfacial velocity, wave characteristics and techniques on CHF, the boiling curve, and the

coalescence and disintegration of fluid particles pressure drop. The CHFs will be correlated as a

are investigated. Special emphasis is placed on function of flow and geometrical variables. The

developing the four-sensor and five-sensor experiments will be complemented by

resistivity probe method and improving the mechanistically based models for CHF under

double-sensor resistivity probe method. A second normal and enhanced conditions.

emphasis is on the system size and entrance

effects on the interfacial characteristics described The experimental facility has been modified to

above. The changes in the interfacial structures permit data acquisition under extreme conditions

and flow regimes as a function of an axial location of flow and heat flux. CHF data have been

are measured experimentally. This information obtained with pure water flowing in plain tubes to

together with the local measurements from the describe the main parametric trends. A

probe method are used to study the mechanisms complementary data base of results from the

of flow regime transitions. This research is part of literature is being assembled for the correlation

a joint program between the University of development.

Wisconsin-Milwaukee (Kojasoy) and Purdue. The

research program is expected to lead to a) local

instrumentation methods for detailed interfacial Rensselaer Polytechnic Institute

characteristics, b) data for local interfacial area, Dept of Mechanical Engineering, $128,000

void fraction, relative velocity and wave Aeronautical Eng & Mechanics 01-A

propagation velocity, and c) phenomenological Troy, NY 12180-3590 91-3

models for interfacial area and interfacial structural

changes. Inelastic Deformation and Damage at High

Temperature

E Krempl

Rensselaer Polytechnic Institute

Dept of Mechanical Eng, $122,000 A combined theoretical and experimental

Aeronautical Eng Mechanics 01-B investigation is performed to study the biaxial

Troy, NY 12180-3590 89-4 deformation and failure behavior of AISI Type 304

Stainless Steel under low-cycle fatigue conditions

Ultimate Umits of Boiling Heat Fluxes at elevated temperature. The purpose is to

A. Bergles, M. Jensen characterize the material behavior in terms of

mathematical equations which are ultimately

This study is directed toward the thermal-hydraulic intended for use in inelastic stress analysis and life

behavior of water and aqueous mixtures, flowing prediction. Creep-fatigue interaction and

in plain tubes and in tubes with enhancement ratchetting are of special concern. The long-term

Engineering Hesearch 40 1991
goal is the development of a finite element experimentally, in order to assess and thoroughly

program that can directly calculate the understand the effect of the proposed closure laws

life-to-crack initiation of a component under a on the void wave eigenvalues of the two-fluid

given load history. model (i.e., to study well-posedness).

For the experiments, an MTS servohydraulic It is intended that the results of this research will

axial/torsion test system is available together with significantly advance the state-of-the-art in the

an MTS Data/Control Processor. Induction two-fluid modeling of two-phase flows such that,

heating (10 kHz frequency), MTS biaxial grips and in the future, multidimensional two-fluid models

an MTS biaxial extensometer are available can be used with confidence for many problems of

together with a reversing direct current potential practical interest.

drop facility. It is intended for early monitoring of

damage during cyclic loading. It has been tested

out at room temperature. Rensselaer Polytechnic Institute

Dept of Chemical Engineering $83,715 Uniaxial and torsional ratchetting experiments Troy, NY 12180-3590 01-C

showed considerable strain accumulation at room 89-3

temperature and they demonstrate that ratchetting Microcomputer Enhanced Optical

is due to viscous effects. Surprisingly, insignificant Investigation of Spreading and Evaporation

ratchetting and rate sensitivity were observed at Processes in Ultra-Thin Films

550, 600 and 650°C for uniaxial tests. This P. Wayner, Jr

unexpected finding was attributed to strain aging

in the stainless steel. A finite deformation theory The physicochemical phenomena associated with

of viscoplasticity based on overstress (VBO) is fluid flow and change-of-phase heat transfer in

being developed and is being implemented into a ultra-thin (thickness less than 10-5 m) liquid films

finite element computer program. To simulate the are being studied. Microscopic image-processing

complex hardening behavior of AISI Type 304 equipment, procedures, and related computer

Stainless Steel during non-proportional loading, programs are being developed to improve data

new hardening rules are under investigation and resolution and automate data acquisition. First, the

are being implemented into the small deformation image processing equipment are being developed

VBO theory developed previously. and used in conjunction with an interferometer

designed to study the transient film thickness in

draining and evaporating films. The glass cell is Rensselaer Polytechnic Institute designed to optimize temperature control,

Dept of Nuc Eng & Eng Physics $122,000 cleanliness and simplicity. The optical data is

Troy, NY 12180-3590 06-C obtained using a video camera attached to a

89-4 microscope through which the interference fringes

The Continuum Modeling of Two-Phase are recorded. Transport processes in polar and

Systems non-polar fluids, with and without heat transfer,

R. Lahey, Jr., D. Drew are being experimentally studied and analyzed.

Using the results of these studies, an ellipsometer

The primary objective of the research being with a complementary interferometer has been

conducted is to develop a mathematically designed and is being constructed. The long term

consistent multidimensional two-fluid model which objective is to determine the heat transfer

agrees with data and satisfies all the constraints characteristics of evaporating ultra-thin films. The

implied by physical laws and the postulates of near term objective is to develop microscopic

continuum mechanics. image-processing equipment and a

complementary heat

To this end, interfacial closure laws are being transfer cell.

developed such that two-fluid models can be used

to predict many important phenomena, such as the

evolution of interfacial area density and flow

regime transition. Void wave phenomena are also

being investigated, both analytically and

Engineering Research 41 1991
Rice University as the new granular high Tc ceramics. Numerical

Dept of Civil Engineering $81,034 simulations of finite temperature, current carrying,

Houston, TX 77251 01-A networks will be carried out to provide a

91-3 characterization of vortex response in nonStochastic Quadrization for Probabilistic equilibrium situations. For periodic networks,

Analysis of Large Compliant Off-Shore current-voltage (I-V) characteristics will be

Structures computed and compared with experimental results.

P. Spanos The effects on resistivity of transitions from pinned

to unpinned or to melted vortex structures, will be

The objective of this research is to study the investigated. For disordered networks, the effects

nonlinear probabilistic dynamics of large structures of pinning in producing metastabe vortex

subjected to nonlinear forces in general, and the structures leading to glassy behavior will be

probabilistic analysis of offshore marine structures explored.

subjected to nonlinear drag forces in particular. To date, simulations have been carried out for two

Almost all structures used in engineering practice dimensional regular Josephson junction arrays, as

are subject to random physical stimuli and respond well as arrays with random vortex pinning sites.

with nonlinear behavior. This is true with energy Various values of applied magnetic field have

production systems such as offshore structures been studied and I-V characteristics and resistivity

subjected to ocean waves. In designing such were computed and related to vortex structure.

structures, the engineer faces problems of almost We have also simulated the equilibrium behavior

unsurmountable complexity. Thus, it is very of fluctuating vortex lines in a three dimensional

important to develop methods of analysis to treat network, as a model for high Tc superconductors.

problems involving randomness and nonlinearity. Melting of the vortex line lattice into a line liquid,

The methods in existence today are highly and properties of the line liquid, have been

approximate and over-simplified. With the level of investigated and compared with recent theoretical

complexity and generality which exist in current results

energy structures, such as the tension leg platform

for offshore oil drilling, current methods of analysis hi s researh ill gr

and design are unwieldy and inadequate, if at all fundamental understanding of behavior in strongly

valid. A method of analysis is needed which fluctuating superconducting materials. The results

features simplicity and the accuracy of nonlinear will have impact in understanding the magnetic

faresponse i pct ad h acr yo. n liproperties of the new high Tc superconductors,

and in the design of Josephson junction arrays for

In the proposed research, a method of analysis is use as microwave detectors and generators.

to be developed that efficiently addresses

problems in nonlinear probabilistic dynamics in

general, and the analysis of offshore structures in University Of Rochester

particular. Dept of Physics and Astronomy $89,667

Rochester, NY 14627 06-C

90-3

University Of Rochester Coherence Effects in Radiative Energy

Dept of Physics and Astronomy $66,138 Transfer

Rochester, NY 14627 06-C E Wolf

89-3

Flux Flow, Pinning, and Resistive Behavior in The main objective of this research is the

Superconducting Networks elucidation of how coherence properties of sources

S. Teltel affect the spatial and the spectral distribution of

energy in optical fields. The clarification of such

The motion of vortex structures, in response to questions is of importance for the theory of

applied currents, is a major source of resistance in radiative energy transfer and for radiometry with

superconducting networks in magnetic fields. sources of different statistical properties. The

Systems of interest include regular Josephson influence of sourcecorrelations in the physical

junction arrays and type II superconductors, such parameters of random media with which a field

Engineering Hesearch 42 1991
may interact on the spectral properties of the in phase space will be investigated using computer

scattered radiation is also being examined. simulations as well as theory. 4) A newly

discovered analogy between the structural

The progress made so far includes the clarification relaxation found in dense atomic fluids and that in

of the relationship between the radiance of a field concentrated solloidal suspensions will be further

produced by a class of partially coherent optical explored. Laboratory experiments, computer

sources and the radiance (specific intensity) of the simulations as well as analytical methods will be

phemomenological theory; elucidation of effects of used.

diffracting apertures on spectra of partially

coherent fields; and formulation of laws for

propagation of the radiance through paraxial Sandia National Laboratories

optical systems. Fluid, Thermal, and $75,000

Structural Sciences Division 03-B

Current research includes the formulation of new Albuquerque, NM 87185 89-1

conservation laws in which spectral changes take

place and investigations of spectral modifications Two-Phase Flow Measurements by NMR

produced in multiple scattering. The possibility of R. Glvler

determining correlation functions of media from

observed spectral changes of scattered radiation This project will develop nuclear magnetic

is also being examined. resonance (NMR) methods to measure velocity

and concentration distributions of both phases in

two-phase flows. Systems to be studied include

The Rockefeller University concentrated suspension flows in circular tubes,

Department of Physics $ 0 solid-liquid flows in Couette geometries as well as

1230 York Avenue 06-C to gas-liquid and liquid-liquid flows.

New York, NY 10021 88-3

One approach to velocity measurements is to

Some Basic Research Problems Related to measure an incremental spatial displacement of

Energy nuclear spins that are noninvasively tagged

E. Cohen whereas another is to measure the phase

evolution of the nuclear spin precession which

The present project is concerned with the following depends on the translational velocity. The first

problems. 1) The approach to thermal equilibrium method is best suited for flows in uniform

of dynamical systems with relatively few degrees- geometries such as pipe flows whereas the

of-freedom is studied. This is of interest not only second, more complex method, is better suited for

for the foundations of statistical mechanics but non-uniform cases such as for nonneutrally

also for chemical and other problems. The buoyant flows in a Couette geometry.

question is: when does equipartition of energy and

other thermal equilibrium properties hold? In order to improve the capabilities of the

Computer as well as theoretical calculations will be apparatus to make rapid measurements, a major

used. 2) An investigation of Lorentz lattice gas instrumentation upgrade is being performed during

cellular automata with independent particles summer and fall of 1991. This consists in a new

moving on a lattice occupied by randomly placed operating system and computer, hardware

scatterers is carried out. Two goals are a closer improvements to the rf electronics, and a shielded

study of (a) the abnormal diffusion found in strictly magnetic field gradient coil system. The studies of

deterministic models and, (b) the connection with concentrated suspensions in pipe flow for velocity

polymer statistics. Computer and analytic and concentration distributions is complete except

approaches will be employed. This investigation for measurements of particle velocities. The next

is also expected to elucidate the connection major experimental emphasis will be on liquidbetween particle motion in lattice gas cellular solid flows in an asymmetric Couette device.

automata and the hydrodynamic behavior of fluids

in general. 3) A possible relation between the This work is carried out in collaboration with the

transport coefficients of a fluid in ordinary space Lovelace Medical Foundation.

and the Lyapunov exponents of the same system

Engineering Hesearch 43 1991
Sandia National Laboratories oxidizer is introduced into a background of

Combustion Research Facility $143,000 hydrocarbon fuel and water at a temperature and

Thermofluids Division 06-B pressure above the thermodynamic critical point of

Uvermore, CA 94550 90-3 the fuel/water mixture. These flames have direct

application to the destruction of aqueous and

Mixing and Phase Change During mixed hazardous wastes, but little is currently

Combustion known about the ignition, extinction, or stability of

A. Kerstein flames at high pressures, particularly flames at

supercritical water conditions. Sandia has built a

The principal focus of this research program is the laboratory-scale supercritical reactor and

development of a turbulent mixing model demonstrated the capability to obtain quasi-steady

applicable to combustion flows. In work to date, a inverse diffusion fames in supercritical mixtures of

novel computational approach has been water and methane. The reactor provides optical

formulated in which turbulent stirring is access to the reaction zone, and a mapping of

represented by non-linear mappings on a line, temperature, species, and velocity fields is

iterated according to a stochastic rule that planned. Both analytical and numerical models of

incorporates key aspects of the Kolmogorov laminar diffusion flames are available to support

cascade picture of turbulence. Computations and the experimental efforts, however these models

analysis demonstrate substantially better predictive must be modified to include a supercritical fluid

capability than achieved by previous models of equation of state and supercritical transport

molecular mixing in turbulent flow. Future work properties.

will involve further analysis of the mathematical

origins of the computed results, refinement of the

model to capture subtle effects such as the University Of Southern

influence of molecular diffusion on turbulent California

transport, and application to unsolved problems of Department of Mechanical Engineerin§124,514

turbulent mixing in non-reacting turbulent shear Los Angeles, CA 90089-1453 01-C

flows and turbulent combusting flows. 91-3

Particle Pressures in Fluidized Beds

Aspects of heterogeneous combustion are also C. Campbell

addressed in this program. Stochastic networkbreakup models are applied, on a macroscopic The particle pressure represents the portion of the

scale, to the morphological evolution of a reacting momentum transport in a fluidized bed that can

porous solid, and on a microscopic scale, to the be attributed to the motion of particles and their

thermochemical dissociation of a macromolecular interactions. Such forces are responsible for the

fuel such as coal. attrition of fluidized particles and postulated

behaviors of the particle pressure have been used

as a mechanism to explain the stability of

Sandia National Laboratories homogeneously fluidized beds. But, until recently,

Combustion Research Facility $123,500 there have been no measurements of the particle

Uvermore, CA 94551-0969 06-B pressure. Preliminary measurements, in gas90-3 fluidized beds, have shown that the particle

Structure of Inverse Diffusion Flames in pressures exerted on the side walls are primarily

Supercritical Fuel/Water Mixtures due to the presence of bubbles and that the

R. Steeper magnitude of the average particle pressure scale

with the bubble size. The purpose of the present

This research project investigates the structure of investigation is to continue this work to better

inverse diffusion flames in supercritical fuel/water understand the mechanisms that lead to particle

mixtures. Inverse diffusion flames have received pressure generation in both gas and liquid

very little attention in the literature although they fluidized beds. Both investigations will be

possess unique characteristics that are applicable performed in two-dimensional beds. In the gas

to chemical processing and materials synthesis. bed, the goal is to determine the distribution of

The focus of this project is the specific class of particle pressure around an injected twoinverse diffusion flames in which a laminar jet of dimensional bubble as a way of understanding the

Engineering Research 44 19
distribution of particle pressure across the bed. Stanford University

The studies in the liquid bed will be used to try Dept of Mechanical Engineering $ 0

and understand the behavior of the particle Stanford, CA 94305-3030 01-B

pressure near the point of initial instability of the 89-3

bed and the pressure that are generated in the Heat Transfer In Three-Dlmenslonal

early stages of unstable behavior. Funding is Turbulent Boundary Layers

scheduled to begin 9/1/91. J. Eatn

The objectives of this research are to identify,

Southwest Research Institute understand, and model the effects of mean flow

6220 Culebra Road $99,912 three dimensionality on turbulent boundary layer

San Antonio, TX 78228-0510 03-B heat transfer. Our previous work has shown that

91-3 vertical mixing through the boundary layer is

Application of Magnetomechanical Hysteresis suppressed by three dimensionality and that the

Modeling to Magnetic Techniques for wall heat transfer coefficient is reduced.

Monitoring Neutron Embrittlement and Biaxial Experiments on embedded longitudinal vortices

Stress have led to the hypothesis that turbulent mixing is

M. Sablik reduced in the boundary layer because naturally

occurring longitudinal vortices deep in the

The objective of this project is to study boundary layer are attenuated by the crossflow.

experimentally and theoretically the effects of The effects are expected to be asymmetric in that

neutron embrittlement and biaxial stress in steels vortices of one sign are attenuated very rapidly

on signals from various magnetic measurement while the effects of opposite sign vortices are more

techniques. It is expected that interaction between persistent.

experiment and modeling will result in the design

of efficient magnetic measurement procedures for The present experiments are examining both the

monitoring neutron embrittlement and biaxial heat transfer and turbulence structure on a large

stress. disk rotating in a quiescent environment. Single

point turbulence measurements have shown that

Magnetic measurement techniques to be assessed the turbulence mixing is suppressed as in other 3D

are: (1) magnetic hysteresis loop measurement of boundary layers. Multipoint correlations with radial

properties like coercivity and permeability; (2) separations show a substantial asymmetry

magabsorption, which involves measurement of supporting our hypothesis. A constant heat flux

the impedance of an rf coil brought close to a disk for accurate measurement of the heat transfer

magnetic sample; (3) Barkhausen noise analysis; coefficient and the turbulent heat flux is now being

(4) magnetically induced velocity change (MIVC) of fabricated.

an ultrasonic wave; and (5) higher order harmonic

analysis of an ac magnetic hysteresis loop. The

model of Sablik et al for magnetic hysteresis and Stanford University

uniaxial stress effects on magnetic properties will Dept of Mechanical Engineering $97,035

be extended to conditions of biaxial stress and Stanford, CA 94305-3030 01-A

neutron embrittlement. The effects of these 91-3

conditions on magnetic probe signals (I) - (5) will Stability and Stress Analyses of Surface

be modeled and compared to experiment. In the Morphology of Elastic and Piezoelectric

case of neutron embrittlement, measurements will Materials

be made on steel samples previously H. Gao

characterized by Charpy tests after being exposed

to various neutron fluences. The goal of this research is to investigate the

mechanical effects of surface morphology of

Results from this project should ultimately assist in elastic dielectric and piezoelectric materials. In

safety monitoring in the nuclear power and gas particular, the project will study the stability of a

~~~~industries. ^ surface ~flat against diffusional perturbations and

the stress concentration caused by slightly

undulating surfaces.

Engineering Research 45 1991
The surface morphology of materials will be the basis of the more appropriate Gibbs free

studied by using a unified perturbation procedure energy.

based on the notion of thermodynamic forces and

the energy momentum tensor. The A portion of our research has as its objective the

thermodynamic forces on material inhomogeneities development of further understanding of subsonic

such as interfaces and inclusions are a measure and supersonic surface waves and interfacial

of the rate at which the total energy of a physical waves as well as of bulk waves in anisotropic

system varies with the configurational change of linear elastic solids. In the past year we have

these inhomogeneities. Within the general shown that it is indeed possible for onemethodology, any type of material and loading component surface waves (surface waves

condition can be studied as long as the proper consisting of a single partial wave or

forces can be identified. By using corresponding inhomogeneous plane wave) to exist in stable

material conservation laws discovered previously, solids and have constructed examples of such

a systematic analysis of surfaces of piezoelectric waves. These waves are necessarily supersonic

solids will be made. Preliminary studies have and are polarized parallel to the boundary of the

shown that under sufficiently large stresses, half-space in which they exist. In addition, we

surfaces of materials become unstable against a have shown that subsonic two-component surface

range of diffusional perturbations bounded by two waves (formed from two partial waves), which are

critical wave lengths. Even a slight undulation known to exist in real crystals, can never be

caused by these unstable diffusional perturbations, polarized parallel to the half-space boundary. We

such as micro-level bumps and troughs, can result are currently developing a numerical scheme for

in a significant stress concentration along a detecting supersonic surface waves and spaces of

material surface. These concentrations may lead "simple reflection" in real crystals.

to mechanical failures along the surface and may

have more consequences for piezoelectric

materials where the deformation is coupled to an Stanford University

applied electric field. There are also suggestions W.W. Hansen Lab of Physics $0

that the stress distributions in a body may be Stanford, CA 94305-3030 03-B

sensitive to the surface morphology. 90-3

Nondestructive Testing

G. Kino Stanford University

Dept of Mechanical Engineering $177,440 The aim of this project is to develop a

Stanford, CA 94305-3030 01-A photothermal microscope for non contact testing of

91-4 materials. Techniques of this kind are particularly

Energy Changes in Transforming Solids well suited to the determination of thermal

G. Herrmann, D. Barnett parameters, and anisotropy of small samples.

In mechanics of solids, defects may be modeled One example of the work is the measurement of

as inclusions or holes and energy changes play a high temperature superconductors over a range of

preponderant role in characterizing a variety of temperatures from room temperature through the

processes. The heterogenization technique critical temperature Tc down to 20°K. A modulated

recently developed with DOE support is most laser beam, focused to less than I m diameter,

useful in this context. It has been further impinges through a sapphire window onto a

extended, providing several universal formulas, sample of Bi-Ca-Sr-Cu-O in a helium cryostat

e.g. for the average stress between two holes or and periodically modulates its temperature. This

inclusions, for inclusions with imperfect interfaces process excites a thermal wave, which can be

and for stresses in cylindrical and plane layered detected by the variation in reflected signal

media. Based on newly found conservation laws, amplitude of a second focused laser beam, due to

interaction forces between two inclusions (defects) the change of refractivity with temperature. The

have been calculated. A new methodology to sample can be rotated under the beams and the

establish conservation laws for dissipative systems thermal diffusion coefficient, its anisotropy and its

has been advanced, and a theory of stressed magnitude can be measured from the phase delay

solids prone to damage is being reformulated on of the thermal wave. By measuring the amplitude

Engineering Hesearch 46 1991
of the thermal wave, material phase changes context of modern supercomputers. For this

associated with superconductivity can be reason work on implementing an adaptive gridding

measured. A pronounced peak in amplitude is procedure has been commenced.

seen at the critical temperature Tc. Even stronger

effects of this type are observed with charge Adaptive gridding allows the grid to be selectively

density waves in a variety of materials. refined only in those areas where high resolution

is required, thus facilitating large savings in both

computational time and memory requirements.

Stanford University

Dept of Civil Engineering $192,040

Environmental Fluid Mechanics Lab 01-B Stanford University

Stanford, CA 94305-4020 90-3 Mechanical Engineering Dept $253,160

Stanford, CA 94305 03-B

Fluid Dynamics of Double Diffusive Systems 88-4

J. Koseff, R. Street, S. Schladow Diagnostics for Plasma Chemistry

C. Kruger, M. Cappelli

This project is focused on processes that occur in

a double-diffusive system subject to external This research is concerned with optical diagnostics

forcing, using a combined experimental and for plasma chemistry and plasma processing, with

numerical approach. In particular it addresses a an emphasis on methods which allow for

water body that is continuously stratified in both departures from local thermodynamic equilibrium

temperature and salinity. The forcing is provided -- such as finite chemical reaction rates,

by a combination of a lateral heat flux and a nonequilibrium electron densities and

surface shear. Double-diffusive instabilities and temperatures, and radiation loss effects. Laser

mixed layer deepening occurs in response to this and other optically based methods are being

forcing, resulting in changes to the vertical and developed for measurements of plasma

horizontal fluxes of heat and salt. The goals are parameters including electron density and

to (1) understand the initiation and evolution of the temperature. The methods under study are

double diffusive instabilities, (2) quantify the effects designed to be applicable whether or not the

on the vertical fluxes, and (3) compare plasma is in local thermodynamic equilibrium, and

observations of the mixed layer deepening to the indeed to assess the importance of nonequilibrium

existing data for singly stratified systems. The effects under conditions of interest in plasma

experimental component has to date concentrated chemistry.

on the effects of lateral heating. A new 4.0 m long

and 0.8 m wide experimental tank, together with Results with an induction plasma facility show

appurtenant facilities for controlling the initial significant nonequilibrium at the exit of a

stratification, has been commissioned. The end downstream quartz test section and suggest

wall of this tank is uniformly heated using a radiant possible errors in conventional diagnostics

source. Fast response thermistor and conductivity assuming local thermodynamic equilibrium.

probes are used to provide vertical profiles, and Measurements of the radiation source strength in

flow visualization is provided by video imaging of argon indicate an order-of-magnitude difference

dye in illuminated planes. Initial findings suggest from values reported earlier at temperatures of

that the nature of resulting convective intrusions is interest in plasma processing.

a function of two dimensionless stability

parameters. The numerical component involves To apply this approach to diagnostics to a realistic

using a finite volume formulation of the non-linear and promising form of plasma processing, we

Navier-Stokes, conservation of mass, and have undertaken experiments on diamond

conservation of species equations in three space synthesis on substrates in the test section of the

dimensions and in time. The experimental results induction torch. Diamond crystals and films have

suggest that the high resolution required to been grown at rates that are at least one order of

satisfactorily represent the intrusion interfaces will magnitude greater than those characteristic of

make a conventional modeling approach very low-pressure diamond synthesis.

difficult, with the number of grid points required to

resolve the interfaces excessive, even in the

Engineering Hesearch 47 1991
Stanford University Programming to bear on finite element

Dept of Chemistry $135,000 optimization problems related to mechanical

Stanford, CA 94305 06-C component shaping. Better analysis,

89-3 approximation and computation methods would

Thermodynamics In Combustion and Engines contribute to the design of lower weight, more

J. Ross energy efficient vehicles and machines. Since for

existing methods each iteration requires a

Research is concerned with the issue of computationally intensive finite element analysis

enhancement of power output in thermal and (FEA), these innovations are intended to reduce

chemical engines by means of external the number of FEA iterations.

perturbations of constraints coupled to

nonlinearities of the mechanism of the engine. This approach has been applied successfully to

The theoretical possibility of an increase in power the shaping of a planar cantilever support for

output of a thermal engine driven by a chemical minimum weight. Three zones: (1) the fillet near

reaction by means of external periodic variations the support, (2) an interior zone free of stress

of reactant influx has been confirmed in a series of concentration, and (3) one near the load - were

experiments. The power output of an engine is modeled approximately by classical solid

necessarily accompanied by dissipation due to mechanics and more precisely by FEA.

irreversible processes essential for power Monotonicity analysis of the classical

production. Hence an increase in power output by approximation identified as critical the shear stress

means of external perturbations usually implies a near the load and the bending stress in the fillet

decrease in dissipation but may also come about and interior zones. This immediately determined

due to a change in the final state of the system. the optimal shape of the interior and load zones.

Increases in efficiency can be achieved for a It also gave the differential equation of the fillet

particular range of frequencies and amplitudes of shape as a function of its variable curvature,

external perturbations which yield resonance initially unknown. FEA-predicted deviations of

effects and appropriate phase shifts of fluxes and fillet stress from the desired value generated a

forces. Theoretical and experimental studies are new curvature function whose integration produced

in progress on optimization of efficiency by choices a much better shape. Only three iterations were

of functional forms of external perturbations. A needed for convergence. The idea is also proving

variational theory has been constructed which practical for deflection- and vibration-limited

gives limits of improvements in efficiency by cantilever situations. A connecting rod vibration

external perturbations. study has shown remarkably large shape

improvement in a single iteration.

Research is in progress on the construction of a

thermodynamic and stochastic theory of Nearing completion is another study of

irreversible processes far from equilibrium. The computational stability in the geometric modeling

theory has been completed for single and multi- of curved surfaces. It has been established that

variable systems with single and multi-variable reproducibility after rotation and other motions is

stationary states. greatly improved by slight relaxation of

interpolation restrictions. This allows compromise

between the two often conflicting parametric

Stanford University placements of the control points. A new universal quadrilateral patch has been developed which will

Dept of Mechanical Engineering $80,000 permit important simplification of scultured surface

Stanford, CA 94305 03-A codes.

88-3

Monotonicity Analysis and Geometric

Programming In Mechanical Shape

Optimization

D. Wilde, S. Sheppard

This theoretical and computational research

intends to bring the theory and practice of

Monotonicity Analysis and Geometric

Engineering Hesearch 48 1991
Stevens Institute Of Technology resulting microstructure in the two flows are very

Dept of Physics and Engineering $ 0 different. The present efforts are directed towards

Hoboken, NJ 07030 06-C developing fast algorithms for numerically solving

87-4 the multi-bubble interactions.

Investigation of Transitions From Order to

Chaos in Dynamical Systems

G. Schmidt University Of Texas At Austin

Ctr for Studies In Statistical Mech $100,003

Coupled nonlinear oscillator systems are of great and Complex Systems 06-C

interest. They describe diverse phenomena such Austin, TX 78712 91-3

as coupled p-n junctions, Josephson junction

arrays, and serve as approximations of nonlinear The Behavior of Matter Under Nonpartial differential equations, describing the onset equilibrium Conditions: Fundamental

of fluid turbulence, reaction diffusion systems, etc. Aspects and Applications

I. Prigogine, T. Petrosky

We have found recently, using renormalizationgroup treatment, that large classes of such

systems have universal properties, i.e. as the This proposal, which is a continuation of previous

parameters of these systems are varied, work deals with the behavior of matter under nonqualitative as well as quantitative predictions can equilibrium conditions in terms of microscopic

be made as to the change of behavior, description. A theoretical framework for integrating

bifurcations, onset of chaos etc. "non-integrable" large Poincare systems will be

applied to the study of a number of interesting

Having performed the abstract analysis, we are situations. (1) Application to interacting fields,

now in the process of applying it to study the including classical and quantum electrodynamics:

behavior of concrete coupled systems, utilizing The method permits the representation of radiation

and checking the general results we obtained. damping as part of the complex spectrum of the

Liouville operator, and avoids the well-known

difficulties of the classical and quantum radiation

Syracuse University damping theory. (2) Numerical validation of the

Dept of Chemical Engineering $60,000 approach: Numerical experiments will be pursued

and Materials Sciences 01-C in order to verify the quantum formulation.

Syracuse, NY 13244-1190 90-2 Especially, the collapse of the wave function and

the appearance of an equilibrium statistical

Numerical and Physical Modelling of Bubbly distribution, as predicted by the theory, will be

Flow Phenomena verified. (3) The present work, already well

A. Sangani advanced for the definition of unstable particles in

the frame of a complex spectral representation,

will be continued. Unstable particles with decaying

The objective of the project is to understand how modes cannot simply be identified, since decaying

the microstructure of bubbly liquids, i.e., the details modes, taken separately, do not carry energy. (4)

of the size, shape and spatial distributions of The theory gives the possibility to derive new

bubbles, depend on the nature of flow and how criteria for the transition to classical chaos by

the overall properties of the flow in turn depend on studying the complex spectrum of the Uouville

the nature of microstructure. A better operator in a form that is appropriate to mapping

understanding of this interdependence is crucial in problems. (5) The theory goes beyond the nonformulating reliable models for the flow of bubbly Markovian master equation and permits a new

liquids. The work during the past year has approach for the study or transport processes

focused on flows that are either oscillatory in (diffusion, viscosity, etc.). (6) Irreversibility

nature as in the propagation of pressure or appears to be of special interest in high-energy

acoustic waves in bubbly liquids or that are nearly problems, and especially to transitions from virtual

homogeneous as in kinematic waves in nearly to real particles.

uniform flow of bubbly liquids. It was found that

the properties of the bubbly liquids and the

Engineering Hesearch 49 1991
University Of Texas At Austin proper design and strength and lifetime

Dept of Physics $144,777 assessments. A new approach to many cracks

Austin, TX 78712 06-C problems based on interrelating the average

87-5 tractions on individual cracks is introduced. Its

Complex Temporal and Spatial Patterns In advantages are that it yields simple analytical

Nonequillbrlum Systems results which are quite accurate up to very high

H. Swinney crack densities and that it can be applied to crack

arrays or arbitrary geometry. Relation between

Dynamical systems methods are being developed deterioration of elastic properties and "damage" is

and used to characterize the formation and discussed.

evolution of temporal and spatial patterns in

systems maintained far from equilibrium. In

particular, experiments and analyses are United Technologies Res Center

considering electrodeposition of fractal metallic Propulsion Science Lab $175,278

clusters, pattern formation in reaction-diffusion East Hartford, CT 06108 03-A

systems, and instabilities in convecting fluids. 89-3

Novel reactors have been developed to search for Laser Diagnostics Of PACVD Processes

chemical patterns (i.e., spatial variations in the W. Roman, S. Hay, F. Otter, A. Eckbreth

chemical composition), and sustained patterns

have been found in several different one- and The research objective is the comprehensive

two-dimensional geometries. Bifurcations in these experimental investigation of the fundamental

patterns are studied by varying control parameters, nonequilibrium reactive plasma assisted chemical

e.g., the concentrations of the feed chemicals or vapor deposition (PACVD) process as applied to

the temperature. The observed two-dimensional hard face coatings (e.g. TiB2 or diamond).

chemical patterns range from the stationary Nonintrusive laser diagnostics (e.g. laser induced

patterns, similar to those predicted by Turing in fluorescence (LIF) and coherent anti-Stokes

1952 but not observed until 1990, to chemical Raman spectroscopy (CARS)) are being used to

turbulence, which is characterized by large probe gas phase species, concentrations and

numbers of defects and a rapid decay of spatial rotational temperatures in situ. Detailed coating

correlations. Much needs to be done, both characterization is accomplished using Auger, Ion

experimentally and theoretically, to characterize Scattering and secondary ion mass spectroscopies

and understand these spatiotemporal patterns. (AES, ISS and SIMS) and complementary

These laboratory experiments together with techniques. In addition, coating characteristics

numerical and analytic studies of models should such as smoothness, adhesion (UTRC custom

provide general insights into the formation and built pin-on-disc apparatus) and hardness (stateevolution of patterns in nonequilibrium systems. of-the-art nanoindenter apparatus) are measured.

Gas phase spectroscopy is interpreted through

chemical kinetic modelling and will be correlated to

Tufts University coating characteristics thus providing a predictive

Dept of Mechanical Engineering $ 0 capability that is severely lacking in the present

Medford, MA 02155 01-A science base of advanced protective coatings.

88-3 These techniques are also applicable to other

Effective Elastic Properties of Cracked Solids processes such as PVD, CVD, combustion and

M. Kachanov thermal plasma deposition. Results to date

include:

The knowledge of effective elastic properties of

solids with cracks appears to be of increasing 1) fabrication of a 5 kW rf PACVD reactor

engineering importance. Extensive microcracking system

in structural elements working under conditions of 2) exploratory spectral emission studies

high temperatures or irradiation, and microcracking 3) development of substrate preparation

in composite materials under fatigue conditions technology and characterization

may noticeably reduce the stiffness of the material 4) implementation of a ultramicrohardness tester

and make it anisotropic. Understanding and and adhesion test apparatus and analysis of

prediction of these changes are essential for coating hardness and elastic modulous

Engineering Research 50 1991
5) coating durability testing using UTRC erosion Washington State University

test facility Dept of Mechanical Engineering $69,000

6) initial characterization of TiB2 and diamond Pullman, WA 99164-2920 01-B

coatings 91-2

7) first tire CARS observation of diborane (B2H) Mass and Energy Coupling Effects In

in a PACVD process Multiphase Free Shear Flows

8) in situ axial concentration and temperature T. Troutt

profiles of key species (diborane and H2)

9) formulation of chemical kinetic models to The primary goal of this research is to determine

account for spectral observations the role organized vortex motions play in the

dispersion of particles by free shear flows. This

research goal has been pursued using analytical,

Washington University numerical and experimental techniques to examine

Department of Systems Science $72,755 the particle dispersion process in plane mixing

and Mathematics 03-A layers and wakes. The results of these studies

Saint Louis, MO 63130 90-3 have shown that the character of the particle

dispersion process in free shear flows is a function

Dynamical Systems with Internal Structure: of a time scale parameter formed between the

A New Approach to the Problem of Analysis ratio of the particle aerodynamic response time

and Robust Design of a Time Varying System and the time scale of the organized vortex motion.

B. Ghosh For intermediate time scale ratio particles two

types of dispersion mechanisms have been

The main objective of the proposed project is to recently identified. In mixing layers, where large

study design problems for linear time-varying scale vortex mergers occur regularly, intermediate

control systems leading to a robust design via an scale particles are concentrated into sheet like

adaptive controller. Specifically, for autoregressive patterns which undergo stretching and folding

moving average systems with time-varying operations. For plane wakes, where large scale

coefficients, it turns out that a good design vortex mergers are not a dominant feature,

strategy is to adaptively assign the parameters of intermediate scale particles are "focussed" into

the closed loop system by a judicious choice of a highly concentrated regions near the vortex

time-varying compensator. The parameters of the boundaries. The resulting order of the

compensator which assign a specified set of self-organized particle dispersion patterns for both

coefficients in the closed loop satisfy a nonlinear mixing layers and wakes can be quantified using

recursion. We propose to study these recursions the fractal correlation dimension. This quantity is

in details. For specific cases, we show that the found to be a strong function of particle time scale

proposed recursion is an Anosov diffeomorphism ratio. Current research efforts are focussed on

on a three-dimensional torus. In particular, such exploring the effects of two-way mass, momentum

a dynamic is chaotic. We feel that our design and energy coupling between the particulate

should try to avoid chaotic dynamics. phase and the carrier fluid. These multiphase

coupling effects may have significant importance

In order to analyze and design a compensator for with regard to predicting the performance of many

a time-varying system it is important to be able to energy conversion systems. New design concepts

estimate the trend, i.e., predict future values of the for multiphase mixing systems are a highly

parameters of the system. An important part of plausible application of these results.

our project is to assume that the parameters

change in accordance with an internal structure

viz. a time series. Our goal is to estimate the

parameters of the internal structure.

Thus we propose to investigate in this project an

identification scheme with internal structure

together with recursive coefficient assignment in

real time in order to generate a desirable

performance in the closed loop.

Engineering Hesearch 51 1991
University Of Wisconsin University Of Wisconsin

Mechanical Engineering Dept $103,855 Dept of Chemical Engineering $108,337

Milwaukee, Wl 53201 01-C Madison, Wl 53706 03-A

90-3 89-3

Interfaclal Area and Interfacial Transfer in New Process Modeling, Design and Control

Two-Phase Flow Systems Strategies for Energy Efficiency, High

G. Kojasoy Product Quality, and Improved Productivity in

the Process Industries

The objective of the research program is to W. Ray

develop instrumentation methods, experimental

data base and analysis leading to predictive The process industries are having great difficulty

models for describing the interfacial structure and competing in the world market because of high

behaviors of two-phase flows. In terms of the flow energy costs, high labor rates, and old technology

structure, the local void fraction, interfacial area for many processes. This project is concerned

concentration, fluid particle size distribution and with the development of process design and

flow patterns in vertical two-phase flow systems control strategies for improving energy efficiency,

are studied in detail. For the purpose of product quality, and productivity in the process

understanding the dynamic behaviors, the industry. In particular, (1) the resilient design and

interfacial velocity, wave characteristics and control of chemical reactors, and (2) the operation

coalescence and disintegration of fluid particles of complex processing systems, will be

are investigated. Special emphasis is placed on investigated. Major emphasis in part (1) will be on

developing the four-sensor and five-sensor two important classes of chemical reactors:

resistivity probe method and improving the polymerization processes and packed bed

double-sensor resistivity probe method. Asecond reactors. In part (2), the main focus will be on

emphasis is on the system size and entrance developing process identification and control

effects on the interfacial characteristics described procedures which allow the design of advanced

above. The changes in the interfacial structures control systems based on limited process

and flow regimes as a function of an axial location information and which will work reliably when

are measured experimentally. This information process parameters change in an unknown

together with the local measurements from the manner. Specific topics to be studied include new

probe method are used to study the mechanisms process identification procedures, nonlinear

of flow regime transitions. This research is part of controller designs, adaptive control methods, and

a joint program between Purdue University (Ishii) techniques for distributed parameter systems.

and the University of Wisconsin-Milwaukee. The Both fundamental and immediately applicable

research program is expected to lead to a) local results are expected. The theoretical

instrumentation methods for detailed interfacial developments are being tested experimentally on

characteristics, b) data for local interfacial area, pilot scale equipment in the laboratory. These

void fraction, relative velocity and wave experiments not only allow improvements in

propagation velocity, and c) phenomenological theoretical work, but also represent real life

models for interfacial area and interfacial structural demonstrations of the effectiveness of the

changes. methods and of the feasibility of implementing

them in an industrial environment. The new

techniques developed in this project will be

incorporated into computer-aided design packages

and disseminated to industry. Therefore, it is

expected that the work will have an impact on

industrial practice.

ngineernng Research 52 1991
Budget Number Index

Mechanical Sciences:

01-A Solid Mechanics: macroscopic aspects of elastic and plastic deformations,

and crack propagation

01-B Heat Transfer

01-C Fluid Mechanics

01-D Tribology

Control Systems and Instrumentation:

03-A Control systems, large scale systems

03-B Instrumentation for hostile environment, and NDE

03-C Intelligent systems

Engineering Data and Analysis:

06-A Thermophysical properties and processes

06-B Combustion

06-C Non-linear dynamics and engineering analysis
Budget Page

Number Number

01-A

Chaos in Fluid-Structure Systems ................................... 1

Bounds on Dynamic Plastic Deformation ............................... 2

Continuum Damage Mechanics II .................................... 2

An Investigation of the Effects of History Dependent Damage in Time Dependent

Fracture Mechanics ............................................. 3

Micromechanical Viscoplastic Stress-Strain Model with Grain Boundary Sliding ... 12

Chaos in Fluid-Structure Systems ................................... 12

A Micromechanical Viscoplastic Stress-Strain Model with Grain Boundary Sliding . . 14

Elastic-Plastic Fracture Analysis Emphasis on Surface Flaws ................ 17

Modeling and Analysis of Surface Cracks .............................. 27

Basic Engineering Sciences of Solids Comminution ....................... 28

Inelastic Deformation and Damage at High Temperature .................... 40

Stochastic Quadrization for Probabilistic Analysis of Large Compliant

Off-Shore Structures ............................................ 42

Stability and Stress Analyses of Surface Morphology of Elastic and

Piezoelectric Materials ........................................... 45

Energy Changes in Transforming Solids ............................... 46

Effective Elastic Properties of Cracked Solids ........................... 50

01-B

Traveling-Wave Convection in Fluid Mixtures ........................... 7

High Flux Film and Transition Boiling ................................ 15

Momentum and Heat Transfer Processes in Viscoelastic Fluids ................ 19

The Impact of Separated Flow on Heat and Mass Transfer ................... 29

Thinning And Rupture of Thin Liquid Films ............................ 34

Radiative Transfer Through an Array of Discrete Surfaces ................... 37

Radiative Transfer Through Arrays of Discrete Surfaces with Fixed Orientation .... 37

Ultimate Limits of Boiling Heat Fluxes ................................ 40

Heat Transfer in Three-Dimensional Turbulent Boundary Layers .............. 45

Fluid Dynamics of Double Diffusive Systems ........................... 47

Mass and Energy Coupling Effects in Multiphase Free Shear Flows ............ 51
01-C

Hydrodynamic Instabilities and Coherent Structures ....................... 1

Basic Studies of Transport Processes in Porous Media ...................... 5

Turbulence Structure and Transport Processes in Wavy Liquid Streams .......... 8

Lift and Drag Forces on Droplets and Particles in Wall-Bounded Flows ......... 11

Experiments in Turbulent Mixing .................................... 13

Two Phase Potential Flow ......................................... 14

Analytical and Experimental Study of Instabilities in Buoyancy-Driven Convection

in Porous Media ............................................... 14

Gas-Liquid Flow in Pipelines ...................................... 18

Numerical and Physical Modeling of Bubbly Flow Phenomena ................ 20

Turbulence Theory and Reduced Hydrodynamic Description .................. 20

Two-Phase Flow Measurements by NMR .............................. 21

Lagrangian Analysis of Contaminant Dispersal in Bounded Turbulent Shear Flows . . 23

Stability and Heat Transfer in Time-Modulated Flows ..................... 24

Dryout in Horizontal and Almost Horizontal Heated Tubes ................ 26

Rheological and Flow Characteristics of Dense Multiphase Slurries Employing a

Bimodal Model ................... ........................ 28

Stability Studies of Core-Annular Flows ............................... 29

Convection and Dispersion in Coarse-Packed Beds ........................ 30

The Rheology of Concentrated Suspensions ............................. 32

Effects of Capillarity of Macroscopic Flow in Porous Media ................. 34

Study of Interfacial Behavior in Cocurrent Gas-Liquid Flows ................. 35

Effect of Forced and Natural Convection on Solidification of Binary Mixtures ..... 39

Interfacial Area and Interfacial Transfer in Two-Phase Flow ................. 40

Microcomputer Enhanced Optical Investigation of Spreading and Evaporation

Processes in Ultra-Thin Films ..................................... 41

Particle Pressures in Fluidized Beds .................................. 44

Numerical and Physical Modeling of Bubbly Flow Phenomena ................ 49

Interfacial Area and Interfacial Transfer in Two-Phase Flow Systems ........... 52

01-D

Cryotribology: Development of Cryotribological Theories and Application to

Cryogenic Devices ............................................. 27

03-A

Modeling for Process Control ...................................... 9

Integration of Redesign Methodologies for Chemical Processes ................ 9

Intelligent Control of Thermal Processes ............................... 17

Model Building, Control and Optimization of Large Scale Systems ............. 18

A General Procedure for the Synthesis of Process Flowsheets ................. 24

Synthesis and Optimization of Integrated Chemical Processes ................. 25

Partial Control of Complex Processing Systems .......................... 32
Monotonicity Analysis and Geometric Programming in Mechanical Shape

O ptim ization ................................................. 48

Laser Diagnostics Of PACVD Processes ................. ............ 50

Dynamical Systems with Internal Structure: A New Approach to the Problem of

Analysis and Robust Design of a Time Varying System .................... 51

New Process Modeling, Design and Control Strategies for Energy Efficiency,

High Product Quality, and Improved Productivity in the Process Industries ....... 52

03-B

Nondestructive Evaluation of Superconductors ........................... 17

Pulse Propagation in Inhomogeneous Optical Fibers ....................... 22

Metal Transfer in Gas Metal Arc Welding .............................. 25

Multivariable Control Of The Gas-Metal Arc Welding Process .............. 26

Development of Measurement Capabilities for the Thermophysical

Properties of Energy-Related Fluids ................................. 31

Quantitative Non-Destructive Evaluation of High Temperature

Superconducting M aterials ........................................ 33

Two-Phase Flow Measurements by NMR .............................. 43

Application of Magnetomechanical Hysteresis Modeling to Magnetic

Techniques for Monitoring Neutron Embrittlement and Biaxial Stress ........... 45

Nondestructive Testing ........................................... 46

Diagnostics For Plasma Chemistry ................................... 47

03-C

Research on a Reconfigurable Modular Manipulator System .................. 10

Neural Learning Formalisms for Global Manipulator Redundancy Resolution

Problems in Unstructured Environments ............................... 19

The Use of Stereo Optical Flow Fields in the Determination of Three-Dimensional

Motion and Stereo Correspondence .................................. 22

The Creation of Multi-Degree-of-Freedom Mechanisms for Robotic Applications . . 33

Center for Engineering Systems Advanced Research (CESAR) ................ 35

06-A

Three Phase System Modelling ..................................... 15

In-Flight Measurement of the Temperature of Small, High Velocity Particles ...... 16

Modeling of Thermal Plasma Processes ................................ 16

Transport Properties Of Disordered Porous Media From The Microstructure ....... 33

Bioprocess Engineering Research for Energy Applications .................... 36

Experimental and Theoretical Studies of Condensation in Multicomponent Systems . . 38
06-B

Experimental and Theoretical Study of Fuel Droplets Subject to Straining Flow .... 6

Controlled Combustion ........................................... 21

Nonuniform Liouville Transformers for Quasi-Homogeneous Optical Fields ....... 38

Mechanisms and Enhancements of Flame Stabilization ..................... 39

Mixing and Phase Change During Combustion ........................... 44

Structure of Inverse Diffusion Flames in Supercritical Fuel/Water Mixtures ....... 44

06-C

Transport in Porous/Disordered Materials .............................. 3

Self-Generated Stochastic Heating in an RF Discharge ..................... 4

Energy and Particle Transport in Random Media ......................... 5

Wave Turbulence and Self-Localization in Continuous Media ................ 5

Signal Processing in Chaos ........................................ 5

Noisy Nonlinear Systems ......................................... 6

Knot Invariants and the Thermodynamics of Lattice Gas Automata ............. 6

Formation of Three-Dimensional Singularities, Regularization Procedures

and Markovian-Multifractal Description of Turbulent Flows ................. 7

Bifurcations and Patterns in Nonlinear Dissipative Systems .................. 8

Topics in Finite-Time Thermodynamics ............................... 10

Fundamentals and Techniques of Nonimaging Optics for Solar Energy Concentration 11

Mixing and Settling in Continuous Metal Production ....................... 13

Studies in Nonlinear Dynamics ..................................... 20

Mathematical Models of Hysteresis ................................... 22

Macrostatistical Hydrodynamics .................................... 29

Thermal Plasma Processing of Materials ............................... 30

Low Resistivity Ohmic Contacts Between Semiconductors and High-Tc

Superconductors ............................................... 31

Studies in Premixed Combustion .................................... 32

Mixing of Immiscible Fluids in Chaotic Flows and Related Issues ............. 35

Turbulence and Spatio-Temporal Chaos ............................... 36

Radiative Interactions with Micromachined Surfaces:

Spectral Angular Polarized Emittance ................................. 37

The Continuum Modeling of Two-Phase Systems ........................ 41

Flux Flow, Pinning, and Resistive Behavior in Superconducting Networks ........ 42

Coherence Effects in Radiative Energy Transfer .......................... 42

Some Basic Research Problems Related to Energy ........................ 43

Thermodynamics in Combustion and Engines ............................ 48

Investigation of Transitions From Order to Chaos in Dynamical Systems ......... 49

The Behavior of Matter Under Nonequilibrium Conditions: Fundamental Aspects

and Applications .............................................. 49

Complex Temporal and Spatial Patterns in Nonequilibrium Systems ............ 50
Principal Investigators

H. Abarbanel 5 J. Georgiadis 14 C. Law 39 J. Ross 48

J. Achenbach 33 B. Ghosh 51 P. Libby 6 M. Sablik 45

A. Acrivos 32 R. Givler 43 A. Lichtenberg 4 A. Sangani 49

G. Ahlers 8 R. Goldstein 29 M. Lieberman 4 S. Schladow 47

S. Altobelli 21 A. Graham 29 K. Lindenberg 6 G. Schmidt 49

G. Andrews 15 P. Griffith 26 R. Littlejohn 20 C. Scott 36

J. Balint 23 1. Grossmann 9 W. Lloyd 17 J. Sengers 31

S. Banerjee 8 T. Hanratty 18 M. Malone 24 S. Sheppard 48

S. Bankoff 34 D. Hardt 26 R Mann 35 R. Shinnar 32

J. Barhen 19 J. Hartnett 19 I. Mayergoyz 22 G. Sivashinsky 32

D. Barnett 46 S. Hay 50 F. McClintock 27 H. Smartt 17

T. Basar 18 W. Haynes 31 M. McCready 35 P. Spanos 42

A. Bergles 40 F. Hayot 36 J. McLaughlin 11 R Steeper 44

P. Bernard 23 G. Herrmann 46 C. Menyuk 22 R. Street 47

R. Berry 10 G. Hetsroni 8 D. Meyer 6 C. Surko 7

L. Biegler 9 F. Incropera 39 M. Miksis 34 H. Swinney 50

H. Brenner 29 M. Ishii 40 M. Moldover 31 S. Teitel 42

F. Brust 3 Y. Iwasa 27 L. Mondy 29 K. Telschow 17

C. Campbell 44 J. Jannson 38 F. Moon 12 C. Thompson 24

D. Cannell 8 C. Jayaprakash 36 M. Morari 9 G. Thompson 9

M. Cappelli 47 M. Jensen 40 J. Moreland 31 S. Torquato 33

A. Caprihan 21 J. Johnson 17 T. Mulcahy 1 T. Troutt 51

I. Catton 4 M. Jones 30 E. Novikov 7 L. Tsai 23

C. Chang 16 E. Jordan 12 A. Oppenheim 21 K. Walker 14

S. Chen 1 D. Joseph 29 F. Otter 50 J. Wallace 23

E. Cohen 43 M. Kachanov 50 J. Ottino 35 G. Wallis 14

S. Davis 34 T. Kanade 10 D. Parks 27 Z. Warhaft 13

J. Douglas 24 A. Kaufman 20 C. Peterson 28 P. Wayner, Jr. 41

D. Drew 41 R. Kayser 31 T. Petrosky 49 J. Welty 37

M. Drost 37 A. Kerstein 44 E. Pfender 30 A. Westerberg 9

J. Duncan 22 T. Keyes 3 F. Pin 35 D. Wilde 48

T. Eagar 25 P. Khosla 10 G. Pomraning 5 G. Wilemski 38

J. Eaton 45 G. Kino 46 I. Prigogine 49 F. Williams 6

A. Eckbreth 50 G. Kojasoy 52 R Probstein 28 R. Winston 11

J. Ekin 31 P. Kokotovic 18 A. Prosperetti 20 L. Witte 15

J. Epstein 17 J. Koseff 47 S. Putterman 5 E. Wolf 42

L. Evans 25 R. Kraichnan 20 J. Ramshaw 16 J. Wolfe 30

J. Fincke 16 D. Krajcinovic 2 W. Ray 52 C. Youngdahl 2

A. Frenkel 1 E. Krempl 40 W. Reuter 17 J. Zemel 37

M. Frish 38 C. Kruger 47 H. Richter 13

E. Fukushima 21 R Lahey, Jr. 41 I. Rinard 32

H. Gao 45 J. Lang 25 W. Roman 50

Engineering Research 1991
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